Joe Biden promised Ukrainian President Volodymyr Zelenskyy, on a historic visit to Washington, that Ukrainians would "never be alone" against Russia and that the United States would help Kyiv "for as long as it takes".
"You will never be alone," the US president said during a joint press conference with Zelenskyy at the White House. "When Ukraine's freedom was threatened, the American people, like generations of Americans before them, did not hesitate.
"We know that Ukraine's struggle is part of something much bigger," Biden added. "The American people know that if we do not stand up to such blatant attacks on freedom, democracy and fundamental principles such as sovereignty and territorial integrity, the world will face far worse consequences.
"We will stand by your side for as long as it takes," he continued, saying he was "not at all worried" about the strength of the Western alliance.
"I have never seen NATO or the EU so united on anything," Biden said. "Putin thought he would weaken NATO, instead he has strengthened NATO," he said.
For his part, Volodymyr Zelenskyy, who was making his first trip abroad since the start of the Russian offensive against Ukraine on 24 February, welcomed the announcement by the United States of the dispatch of a Patriot air defence system, the most sophisticated available to the US army.
"This is a very important step in creating a secure airspace for Ukraine," he told the press, according to an interpreter's translation, alongside President Joe Biden.
But the "just peace" Mr Biden spoke of earlier to end the conflict "does not imply any compromise on the sovereignty, freedom and territorial integrity of my country", the Ukrainian president insisted.
Earlier, the two presidents held talks for more than two hours, and in brief remarks before their Oval Office meeting, Biden said the US and Ukraine would continue to project a “united defense” as Russia wages a “brutal assault on Ukraine's right to exist as a nation.”
Russia is “trying to use winter as a weapon, but Ukrainian people continue to inspire the world,” Biden said. He told Zelenskyy that ”it's an honor to be by your side."
The Ukrainian president thanked Biden, US lawmakers and “ordinary people” of America for their support. Zelenskyy, who who first traveled by train to Poland before boarding a US military plane to the US, said he wanted to visit earlier and his visit now showed the “situation is under control, because of your support.”
The highly sensitive trip was taking place after 10 months of a brutal war that has seen tens of thousands of casualties on both sides and devastation for Ukrainian civilians. Just before his arrival, the US announced its largest single delivery of arms to Ukraine, including Patriot surface-to-air missiles, and Congress planned to vote on a spending package that includes about $45 billion (€42.4b) in emergency assistance to Ukraine.
Zelenskyy headed abroad after making a daring and dangerous trip Tuesday to what he called the hottest spot on the 1,300-kilometer (800-mile) front line of the war, the city of Bakhmut in Ukraine’s contested Donetsk province. He praised Ukrainian troops for their “courage, resilience and strength” as artillery boomed in the background.