STORY: U.S. Secretary of State Antony Blinken met with Ukrainian President Volodmyr Zelenskiy in Kyiv on Tuesday, the first visit by a senior U.S. official since Congress passed a long-delayed $61 billion aid package for the country.Blinken acknowledged that the delay had made Ukraine more vulnerable to Russian attacks, but he pledged unwavering U.S. support going forward."We know this is a challenging time, but we also know that in the near term the assistance is now on the way, some already arrived, more that will be arriving. And that’s going to make a real difference against the ongoing Russian aggression on the battlefield."U.S. military aid had been blocked by Republicans in Congress until they finally allowed a vote last month, when it passed with support from both parties."...big appreciation from Ukrainians to Americans for this."Zelenskiy said his country was thankful for the bipartisan support but added that more help was needed, as Russia mounts fresh attacks in eastern Ukraine."The first, the decision on the package was crucial. For us, it’s very important to get it as quick as possible. The second one, point, it's air defense, the biggest deficit for us. I think that’s the biggest problem, yes. We need, really we need today two Patriots for Kharkiv, for Kharkiv region because people there are under attack, civilians and warriors, everybody there is under Russian missiles." Blinken’s visit comes days after Russia launched a ground incursion into the north of Kharkiv, opening a new front and stretching Ukraine's soldiers.During a speech, Blinken took aim at Russian President Vladimir Putin, and said the U.S. intends to seize Russian assets."What Putin destroyed, Russia should and must pay to rebuild. [FLASH] Our Congress has given us the power to seize Russian assets in the United States. We intend to use it."Russia now controls about 18% of Ukraine and has been gaining ground since the failure of last year's counter-offensive to make serious inroads against Russian troops.