A Ukrainian service member smokes in a trench at a position near the frontline town of Bakhmut, amid Russia's attack on Ukraine, in Donetsk region, Ukraine May 23, 2023. REUTERS/Yevhenii Zavhorodnii 

A Ukrainian service member gestures in a trench at a position near the frontline town of Bakhmut, amid Russia's attack on Ukraine, in Donetsk region, Ukraine May 23, 2023. REUTERS/Yevhenii Zavhorodnii 

A Ukrainian service member moves along a trench at a position near the frontline town of Bakhmut, amid Russia's attack on Ukraine, in Donetsk region, Ukraine May 23, 2023. REUTERS/Yevhenii Zavhorodnii 

A Ukrainian service member stands in a trench at a position near the frontline town of Bakhmut, amid Russia's attack on Ukraine, in Donetsk region, Ukraine May 23, 2023. REUTERS/Yevhenii Zavhorodnii 

A woman poses for a photo under cherry blossoms in a park in Kyiv, Ukraine, May 4, 2023. REUTERS/Alina Smutko 

A woman sniffs cherry blossoms next to trenches in a park in Kyiv, Ukraine May 4, 2023. REUTERS/Alina Smutko 

A woman takes a picture of cherry blossoms next to trenches in a park in Kyiv, Ukraine May 4, 2023. REUTERS/Alina Smutko 

A boy plays around iron defensive hedgehogs in a park in Kyiv, Ukraine May 4, 2023. REUTERS/Alina Smutko 

A women takes a picture under cherry blossoms in a park in Kyiv, Ukraine May 4, 2023. REUTERS/Alina Smutko 

A girl plays next to trenches in a park in Kyiv, Ukraine May 4, 2023. REUTERS/Alina Smutko 

Boys play next to trenches under cherry blossoms in a park in Kyiv, Ukraine May 4, 2023. REUTERS/Alina Smutko 

People take pictures under cherry blossoms in a park in Kyiv, Ukraine May 4, 2023. REUTERS/Alina Smutko TPX IMAGES OF THE DAY 

A woman takes a selfie under cherry blossoms next to trenches in a park in Kyiv, Ukraine May 4, 2023. REUTERS/Alina Smutko 

A woman takes a picture of her child under cherry blossoms in a park in Kyiv, Ukraine May 4, 2023. REUTERS/Alina Smutko 

A boy plays around iron defensive hedgehogs under cherry blossoms in a park in Kyiv, Ukraine May 4, 2023. REUTERS/Alina Smutko 

Girls walk under cherry blossoms next to trenches in a park in Kyiv, Ukraine May 4, 2023. REUTERS/Alina Smutko 

A woman takes a picture of cherry blossoms in a park in Kyiv, Ukraine May 4, 2023. REUTERS/Alina Smutko 

Iraqi workers place a storm sewer pipe into a trench on the outskirts of Sadr city district of Baghdad,Iraq May 1, 2023. The government has kicked off the largest effort to refurbish Baghdad since the 2003 U.S invasion, including renovating the facades of buildings damaged by war and revamping parks and promenades that hug the Tigris River that bisects the city. REUTERS/Thaier Al-Sudani 

Iraqi workers place a storm sewer pipe into a trench on the outskirts of Sadr city district of Baghdad,Iraq May 1, 2023. The government has kicked off the largest effort to refurbish Baghdad since the 2003 U.S invasion, including renovating the facades of buildings damaged by war and revamping parks and promenades that hug the Tigris River that bisects the city. REUTERS/Thaier Al-Sudani 

A Ukrainian service member Oleksandr, 44, holds ammunition for a machine gun in a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

A Ukrainian serviceman pets kittens in a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

Ukrainian service members are seen in a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

A Ukrainian service member smokes in a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

Ukrainian service members walk in a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

Ukrainian service members walk in a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

A Ukrainian service member is seen in a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

A Ukrainian service member walks in a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

A Ukrainian service member Oleksandr, 44, cleans mud from the bottom of a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

A Ukrainian service member Oleksandr, 44, cleans mud from the bottom of a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

Ukrainian service members are seen in a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

A Ukrainian service member Oleksandr, 44, is seen in a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

A Ukrainian service member looks through a monocular in a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

A Ukrainian serviceman pets a kitten in a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

A Ukrainian service member Oleksandr, 44, is seen in a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

Ukrainian service members load ammunition for a machine gun in a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

A Ukrainian serviceman pets a kitten in a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

Ukrainian service members are seen in a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

Ukrainian service members walk in a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

Ukrainian service members rest near a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

A Ukrainian service member walks in a trench at a front line, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

A Ukrainian service member Oleksandr, 44, cleans mud from the bottom of a trench at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine April 28, 2023. REUTERS/Sofiia Gatilova 

How Russia has fortified parts of Ukraine ahead of a possible counteroffensive Russian defensive fortifications have sprung up along, behind and sometimes far removed from the front lines. 

How Russia has fortified parts of Ukraine ahead of a possible counteroffensive Russian defensive fortifications have sprung up along, behind and sometimes far removed from the front lines. 

Ukrainian service man with 80th brigade prepares coffee and tea in a trench in a forward position during heavy fighting amid Russia?s attack on Ukraine, close to Bakhmut Ukraine, April 16, 2023. REUTERS/Kai Pfaffenbach 

Ukrainian service man with 80th brigade listens to some incoming artillery shelling while preparing coffee and tea in a trench in a forward position during heavy fighting amid Russia?s attack on Ukraine, close to Bakhmut Ukraine, April 16, 2023. REUTERS/Kai Pfaffenbach 

Ukrainian service man with 80th brigade prepares coffee and tea in a trench in a forward position during heavy fighting amid Russia?s attack on Ukraine, close to Bakhmut Ukraine, April 16, 2023. REUTERS/Kai Pfaffenbach 

Military chaplain Yurii looks on in a trench after an Orthodox Easter service for Ukrainian servicemen at their position, as Russia's attack on Ukraine continues, in Kharkiv region, Ukraine April 15, 2023. REUTERS/Sofiia Gatilova 

A Ukrainian service woman carries a doll as a talisman next to her AK47 magazines in a trench near the frontline during heavy fighting amid Russia's attack on Ukraine, close to Bakhmut, Ukraine, April 13, 2023. REUTERS/Kai Pfaffenbach 

Ukrainian artillery unit member sports a patch of Ukrainian writer Taras Shevchenko as he operates from muddy trenches near the frontline during heavy fighting amid Russia's attack on Ukraine, close to Bakhmut, Ukraine, April 13, 2023. REUTERS/Kai Pfaffenbach 

Ukrainian artillery unit operates from muddy trenches near the frontline during heavy fighting amid Russia's attack on Ukraine, close to Bakhmut, Ukraine, April 13, 2023. REUTERS/Kai Pfaffenbach 7 

Ukrainian artillery unit operates from muddy trenches near the frontline during heavy fighting amid Russia's attack on Ukraine, close to Bakhmut, Ukraine, April 13, 2023. REUTERS/Kai Pfaffenbach TPX IMAGES OF THE DAY 

Ukrainian artillery unit operates from muddy trenches near the frontline during heavy fighting amid Russia's attack on Ukraine, close to Bakhmut, Ukraine, April 13, 2023. REUTERS/Kai Pfaffenbach 

Ukrainian artillery unit operates from muddy trenches near the frontline during heavy fighting amid Russia's attack on Ukraine, close to Bakhmut, Ukraine, April 13, 2023. REUTERS/Kai Pfaffenbach 

Ukrainian artillery unit operates from muddy trenches near the frontline during heavy fighting amid Russia's attack on Ukraine, close to Bakhmut, Ukraine, April 13, 2023. REUTERS/Kai Pfaffenbach 

Ukrainian artillery unit operates from muddy trenches near the frontline during heavy fighting amid Russia's attack on Ukraine, close to Bakhmut, Ukraine, April 13, 2023. REUTERS/Kai Pfaffenbach 

Ukrainian artillery unit operates from muddy trenches near the frontline during heavy fighting amid Russia's attack on Ukraine, close to Bakhmut, Ukraine, April 13, 2023. REUTERS/Kai Pfaffenbach 

Ukrainian artillery unit operates from muddy trenches near the frontline during heavy fighting amid Russia's attack on Ukraine, close to Bakhmut Ukraine, April 13, 2023. REUTERS/Kai Pfaffenbach 

Ukrainian artillery unit operates from muddy trenches near the frontline during heavy fighting amid Russia's attack on Ukraine, close to Bakhmut, Ukraine, April 13, 2023. REUTERS/Kai Pfaffenbach 

A Ukrainian service member is seen in a trench at a position on a front line, as Russia's attack on Ukraine continues, near the city of Bakhmut, Ukraine April 10, 2023. REUTERS/Oleksandr Klymenko