Presidents from countries on Russia's doorstep visit Ukraine

Kyiv (Ukraine): The presidents of four countries on Russia's doorstep visited Ukraine on Wednesday and underscored their support for the embattled country, where they saw heavily damaged buildings and demanded accountability for what they called war crimes carried out by Russian forces.

The visit by the presidents of Poland, Lithuania, Latvia and Estonia was a strong show of solidarity from the countries on NATO's eastern flank, three of them like Ukraine once part of the Soviet Union.

The leaders traveled by train to the Ukrainian capital, Kyiv, to meet with their counterpart Volodymyr Zelenskyy, and visited Borodyanka, one of the nearby towns where evidence of atrocities was found after Russian troops withdrew to focus on the country's east.

The fight for Europe's future is happening here, Lithuanian President Gitanas Nauseda said, calling for tougher sanctions, including against Russia's oil and gas shipments and all the country's banks.

Elsewhere, in one of the most crucial battles of the war, Russia said more than 1,000 Ukrainian troops had surrendered in the besieged southern port of Mariupol, where Ukrainian forces have been holding out in pockets of the city. A Ukrainian official denied the claim, which could not be verified.

Russia invaded on Feb. 24 with the goal, according to Western officials, of taking Kyiv, toppling the government and installing a Moscow-friendly one. But the ground advance slowly stalled and Russia lost potentially thousands of fighters. The conflict has killed untold numbers of Ukrainian civilians and forced millions more to flee. It also has rattled the world economy, threatened global food supplies and shattered Europe's post-Cold War balance.

Appearing alongside Zelenskyy in an ornate room in Kyiv's historic Mariinskyi Palace on Wednesday, Nauseda, Estonian President Alar Karis, Poland's Andrzej Duda and Egils Levits of Latvia reiterated their commitment to supporting Ukraine politically and with military aid.

We know this history. We know what Russian occupation means. We know what Russian terrorism means," Duda said. He added that both those who committed war crimes and those who gave the orders should be held accountable.

If someone sends aircraft, if someone sends troops to shell residential districts, kill civilians, murder them, this is not war," he said. "This is cruelty, this is banditry, this is terrorism.

In his daily late-night address, Zelenskyy noted that the prosecutor of the International Criminal Court, Karim Khan, visited the Kyiv suburb of Bucha, where more than 400 bodies were found, on Wednesday as an ICC investigation gets underway. Evidence of mass killings of civilians was found there after the Russian retreat.

It is inevitable that the Russian troops will be held responsible. We will drag everyone to a tribunal, and not only for what was done in Bucha, Zelenskyy said.

Also Wednesday, a report commissioned by the Organization for Security and Cooperation in Europe found clear patterns of (international humanitarian law) violations by the Russian forces in their conduct of hostilities. It was written by experts selected by Ukraine and published by the Vienna-based organization, which promotes security and human rights.

The report said there were also violations by Ukraine, but concluded those committed by Russia are by far larger in scale and nature.

Russian President Vladimir Putin has denied his troops committed atrocities, saying Tuesday that Moscow had no other choice but to invade and would continue until its full completion and the fulfillment of the tasks that have been set. He insisted Russia's campaign was going as planned despite a major withdrawal after its forces failed to take the capital and suffered significant losses.

Russian troops are now gearing up for a major offensive in the eastern Donbas region, where Moscow-allied separatists and Ukrainian forces have been fighting since 2014, and where Russia has recognized the separatists' claims of independence.

A key piece of the Russian campaign is Mariupol, which lies in the Donbas and which the Russians have pummeled since nearly the start of the war.

Russian Defense Ministry spokesman Maj.-Gen. Igor Konashenkov said 1,026 troops from the Ukrainian 36th Marine Brigade surrendered at a metals factory in the city. But Vadym Denysenko, adviser to Ukraine's interior minister, rejected the claim, telling Current Time TV that the battle over the seaport is still ongoing today.

It was unclear when a surrender may have occurred or how many forces were still defending Mariupol.