U.S. lawmakers could vote as soon as Tuesday on a bill authorizing at least $33 billion in military and humanitarian aid for Ukraine.
Ahead of the possible vote in the House of Representatives, President Joe Biden said his administration has "nearly exhausted" his authority to send weapons and other military equipment from Pentagon stockpiles.
Secretary of State Antony Blinken and Defense Secretary Lloyd Austin issued a similar appeal in a letter to lawmakers, urging them to act before May 19 when they expect the existing drawdown will run out.
Senate Minority Leader Mitch McConnell said Monday that while the new measure under consideration "may adjust some in the process," he is focused on "getting it done quickly."
Biden signed separate legislation Monday giving him new power to expedite the shipment of military equipment and supplies to Ukraine under a program modeled after a World War II law that originally assisted European countries fighting Nazi Germany.
The new measure gives the U.S. leader the authority to reach quick agreements with Ukraine as well as other Eastern European countries for the shipment of the equipment, bypassing some of Washington's current burdensome bureaucratic rules.
In a rarity for politically divided Washington, Congress overwhelmingly passed the legislation last month in a continuing show of support for the Kyiv government as it battles Russian forces.
Ukrainian President Volodymyr Zelenskyy said in a late Monday address that history will hold Russia responsible for its actions in Ukraine, and that Europe has to consider the price Russia should pay "for bringing the evil of total war to Europe again."
"And we, Ukrainians, will continue to work toward our defense, our victory and on restoring justice. Today, tomorrow and any other day that is necessary to free Ukraine from the occupiers," Zelenskyy said.
The head of the U.N.'s human rights monitoring mission in Ukraine, Matilda Bogner, told reporters Tuesday that her office had confirmed more than 7,000 civilian casualties, including 3,381 deaths, since Russia launched its attack on Ukraine, and that the real toll is far higher.
"We have been working on estimates, but all I can say for now is that it is thousands higher than the numbers we have currently given to you," Bogner said at a press briefing in Geneva, when asked about the total number of deaths and injuries. "The big black hole is really Mariupol where it has been difficult for us to fully access and to get fully corroborated information," Bogner said.
She said the number of civilian casualties and damage to civilian areas suggests violations against prohibitions of indiscriminate attacks and the requirement to take precautions to avoid harming civilians.
Bogner said the U.N. has received reports of 300 unlawful killings in Bucha, a Kyiv suburb where Russian forces have been accused of committing atrocities.
German Foreign Minister Annalena Baerbock made an unannounced visit to Ukraine on Tuesday that included a stop in Bucha.
Baerbock is the latest international figure to go to Ukraine to show support and get a first-hand view of the situation in the country. U.S. first lady Jill Biden and Canadian Prime Minister Justin Trudeau made separate visits to Ukraine on Sunday.
Russian President Vladimir Putin on Monday blamed Western nations for his invasion of Ukraine, saying Russia acted in response to "an absolutely unacceptable threat next to our borders."
But the longtime Russian leader did not announce any change in Moscow's military campaign or declare victory, suggesting that his 10-week offensive would continue with attacks on Ukrainian strongholds in the eastern part of the country after Russia failed to topple Zelenskyy or capture the capital Kyiv.
Putin addressed a Red Square military parade in a Victory Day celebration commemorating the defeat of Germany in World War II. He spoke of Russia's demands for security guarantees, which Russia made in the months ahead of its February 24 invasion even as it repeatedly insisted it had no plans to attack its neighbor.
Weeks ago, U.S. and NATO leaders met with Russian officials multiple times but rejected certain Russian demands, including a pledge that Ukraine would never join NATO.
"NATO countries did not want to listen to us, meaning that they in fact had entirely different plans, and we saw this," Putin said Monday. "Openly, preparations were under way for another punitive operation in Donbas, the invasion of our historical lands, including Crimea."
Some information for this story came from The Associated Press, Agence France-Press and Reuters.