Mike Elm, a Scottish cyclist who left Edinburgh last November on a two-year-long cycling journey to collect stories of people and businesses responding to climate crisis and his colleague Rosie Watson on a similar journey on foot are stuck following the coronavirus disease (COVID-19) travel restrictions in Prizren, Kosovo April 20, 2020. REUTERS/Bardh Krasniqi

Mike Elm, a Scottish cyclist who left Edinburgh last November on a two-year-long cycling journey to collect stories of people and businesses responding to climate crisis and his colleague Rosie Watson on a similar journey on foot are stuck following the coronavirus disease (COVID-19) travel restrictions in Prizren, Kosovo April 20, 2020. REUTERS/Bardh Krasniqi

Mike Elm, a Scottish cyclist who left Edinburgh last November on a two-year-long cycling journey to collect stories of people and businesses responding to climate crisis and his colleague Rosie Watson on a similar journey on foot are stuck following the coronavirus disease (COVID-19) travel restrictions in Prizren, Kosovo April 20, 2020. REUTERS/Bardh Krasniqi

Mike Elm, a Scottish cyclist who left Edinburgh last November on a two-year-long cycling journey to collect stories of people and businesses responding to climate crisis and his colleague Rosie Watson on a similar journey on foot are stuck following the coronavirus disease (COVID-19) travel restrictions in Prizren, Kosovo April 20, 2020. REUTERS/Bardh Krasniqi

Mike Elm, a Scottish cyclist who left Edinburgh last November on a two-year-long cycling journey to collect stories of people and businesses responding to climate crisis and his colleague Rosie Watson on a similar journey on foot are stuck following the coronavirus disease (COVID-19) travel restrictions in Prizren, Kosovo April 20, 2020. REUTERS/Bardh Krasniqi

Supporters of Democratic presidential candidate Pete Buttigieg hold campaign signs as they wait to see him during a campaign appearance at Elm Street Middle School in Nashua, New Hampshire, U.S. February 9, 2020. REUTERS/Jim Bourg

New Hampshire residents and supporters of Democratic U.S. presidential candidate Pete Buttigieg wait in a long line in the cold to see him make a campaign appearance at Elm Street Middle School in Nashua, New Hampshire, U.S. February 9, 2020. REUTERS/Jim Bourg

New Hampshire residents and supporters of Democratic U.S. presidential candidate Pete Buttigieg wait in a long outdoor line in the cold to see him make a campaign appearance at Elm Street Middle School in Nashua, New Hampshire, U.S. February 9, 2020. REUTERS/Jim Bourg

Supporters of Democratic presidential candidate Pete Buttigieg hold campaign signs as they wait to see him during a campaign appearance at Elm Street Middle School in Nashua, New Hampshire, U.S. February 9, 2020. REUTERS/Jim Bourg

Democratic 2020 U.S. presidential candidate Pete Buttigieg waves goodbye to the crowd as he leaves a campaign rally and Get Out the Vote event at Elm Street Middle School in Nashua, New Hampshire, U.S., February 9, 2020. REUTERS/Jim Bourg

Democratic 2020 U.S. presidential candidate Pete Buttigieg leaves a campaign rally and Get Out the Vote event at Elm Street Middle School in Nashua, New Hampshire, U.S., February 9, 2020. REUTERS/Jim Bourg

Democratic 2020 U.S. presidential candidate Pete Buttigieg addresses a crowd at a campaign rally and Get Out the Vote event at Elm Street Middle School in Nashua, New Hampshire, U.S., February 9, 2020. REUTERS/Jim Bourg

Democratic 2020 U.S. presidential candidate Pete Buttigieg addresses a crowd at a campaign rally and Get Out the Vote event at Elm Street Middle School in Nashua, New Hampshire, U.S., February 9, 2020. REUTERS/Jim Bourg

Democratic 2020 U.S. presidential candidate Pete Buttigieg addresses a crowd at a campaign rally and Get Out the Vote event at Elm Street Middle School in Nashua, New Hampshire, February 9, 2020. REUTERS/Jim Bourg

Democratic 2020 U.S. presidential candidate Pete Buttigieg arrives on stage to address a large crowd at a campaign rally and Get Out the Vote event at Elm Street Middle School in Nashua, New Hampshire, February 9, 2020. REUTERS/Jim Bourg

Democratic 2020 U.S. presidential candidate Pete Buttigieg addresses a crowd at a campaign rally and Get Out the Vote event at Elm Street Middle School in Nashua, New Hampshire, February 9, 2020. REUTERS/Jim Bourg

Democratic 2020 U.S. presidential candidate Pete Buttigieg addresses a large crowd at a campaign rally and Get Out the Vote event at Elm Street Middle School in Nashua, New Hampshire, February 9, 2020. REUTERS/Jim Bourg

New Hampshire residents and supporters of Democratic U.S. presidential candidate Pete Buttigieg wait in a long line in the cold to see him make a campaign appearance at Elm Street Middle School in Nashua, New Hampshire, U.S. February 9, 2020. REUTERS/Jim Bourg

Supporters of Democratic presidential candidate Pete Buttigieg hold campaign signs as they wait to see him during a campaign appearance at Elm Street Middle School in Nashua, New Hampshire, U.S. February 9, 2020. REUTERS/Jim Bourg

Supporters of Democratic presidential candidate Pete Buttigieg hold campaign signs as they wait to see him during a campaign appearance at Elm Street Middle School in Nashua, New Hampshire, U.S. February 9, 2020. REUTERS/Jim Bourg

New Hampshire residents and supporters of Democratic U.S. presidential candidate Pete Buttigieg wait in a long outdoor line in the cold to see him make a campaign appearance at Elm Street Middle School in Nashua, New Hampshire, U.S. February 9, 2020. REUTERS/Jim Bourg

New Hampshire residents and supporters of Democratic U.S. presidential candidate Pete Buttigieg wait in a long line outside in the cold to see him make a campaign appearance at Elm Street Middle School in Nashua, New Hampshire, U.S. February 9, 2020. REUTERS/Jim Bourg

New Hampshire residents and supporters of Democratic U.S. presidential candidate Pete Buttigieg wait in a long line outside in the cold to see him during a campaign appearance at Elm Street Middle School in Nashua, New Hampshire, U.S. February 9, 2020. REUTERS/Jim Bourg

New Hampshire residents and supporters of Democratic presidential candidate Pete Buttigieg wait in a long line outside to see him during a campaign appearance at Elm Street Middle School in Nashua, New Hampshire, U.S., February 9, 2020. REUTERS/Jim Bourg

A climate change activist in a polar bear costume stands with New Hampshire residents and supporters of Democratic U.S. presidential candidate Pete Buttigieg waiting in the cold to see him make a campaign appearance at Elm Street Middle School in Nashua, New Hampshire, U.S. February 9, 2020. REUTERS/Jim Bourg

The U.S. Embassy stands in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

The U.S. Embassy stands in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

The U.S. Embassy stands in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

The U.S. Embassy stands in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

The U.S. Embassy stands in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

The US flag flies outside the U.S. Embassy in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

The U.S. Embassy stands in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

A visitor tries to enter the visa section of the U.S. Embassy in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

The U.S. Embassy stands in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

An exit sign sits on the pavement outside the U.S. Embassy in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

The U.S. Embassy stands in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

An exit sign sits on the pavement outside the U.S. Embassy in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

The U.S. Embassy stands in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

The U.S. Embassy stands in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

The U.S. Embassy stands in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

The U.S. Embassy stands in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

A pedestrian walks past the U.S. Embassy in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

The US flag flies outside the U.S. Embassy in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

The U.S. Embassy stands in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

The U.S. Embassy stands in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

The U.S. Embassy stands in Nine Elms in London, Britain May 1, 2018. REUTERS/Simon Dawson

The US flag flies outside the new U.S. Embassy in Nine Elms in London, Britain January 12, 2018. REUTERS/Peter Nicholls TPX IMAGES OF THE DAY

The final pieces of construction work are completed on the new U.S. Embassy in Nine Elms in London, Britain January 12, 2018. REUTERS/Peter Nicholls

The final pieces of construction work are completed on the new U.S. Embassy in Nine Elms in London, Britain January 12, 2018. REUTERS/Peter Nicholls

The final pieces of construction work are completed on the new U.S. Embassy in Nine Elms in London, Britain January 12, 2018. REUTERS/Peter Nicholls

The final pieces of construction work are completed on the new U.S. Embassy in Nine Elms in London, Britain January 12, 2018. REUTERS/Peter Nicholls

The US flag flies outside the new U.S. Embassy in Nine Elms in London, Britain January 12, 2018. REUTERS/Peter Nicholls

The newly built U.S. Embassy can be seen from across the River Thames in Nine Elms in London, Britain, January 12, 2018. REUTERS/Peter Nicholls

The newly built U.S. Embassy can be seen from across the River Thames in Nine Elms in London, Britain, January 12, 2018. REUTERS/Peter Nicholls

The newly built U.S. Embassy can be seen from across the River Thames in Nine Elms in London, Britain, January 12, 2018. REUTERS/Peter Nicholls

The newly built U.S. Embassy can be seen from across the River Thames in Nine Elms in London, Britain, January 12, 2018. REUTERS/Peter Nicholls

The newly built U.S. Embassy can be seen from across the River Thames in Nine Elms in London, Britain, January 12, 2018. REUTERS/Peter Nicholls

The newly built U.S. Embassy can be seen from across the River Thames in Nine Elms in London, Britain, January 12, 2018. REUTERS/Peter Nicholls

The newly built U.S. Embassy can be seen from across the River Thames in Nine Elms in London, Britain, January 12, 2018. REUTERS/Peter Nicholls

Construction cranes are seen in operation around Battersea Power Station in the Nine Elms area of London, Britain, October 25, 2017. REUTERS/Toby Melville