U.S. President Joe Biden has invited his Ukrainian counterpart Volodymyr Zelenskyy for talks on Tuesday in Washington, the White House said, as the U.S. leader's Democratic Party struggles to make progress in congressional negotiations to secure additional aid for the war-torn country.

"As Russia ramps up its missile and drone strikes against Ukraine, the leaders will discuss Ukraine's urgent needs and the vital importance of the United States' continued support at this critical moment," White House spokeswoman Karine Jean-Pierre said in a statement released Sunday.

U.S. President Joe Biden (L) delivers a speech at an event with Group of Seven countries' leaders and Ukrainian President Volodymyr Zelenskyy (R) in Vilnius on July 12, 2023, as a NATO summit is held in the Lithuanian capital. (Kyodo) ==Kyodo

Zelenskyy's office said he will arrive in Washington on Monday and major topics of discussion will include the continuation of defense cooperation between the two countries, "particularly specific joint projects on the production of weapons and air defense systems" and coordination in 2024.

His visit comes as the war between Israel and the Palestinian militant group Hamas has diverted attention from Russia's invasion of Ukraine, while the fate of Biden's $106 billion supplementary budget request to Congress, featuring $61.4 billion in aid for Kyiv, remains up in the air.

Biden and White House officials have raised the alarm for weeks about funding for Ukraine running out which would play into Russian President Vladimir Putin's hands.

But U.S. congressional Republicans have increasingly expressed skepticism about providing more aid to Ukraine.

On Wednesday, Biden delivered a speech urging Congress to swiftly pass the proposed budget for national security, which also includes funding for Israel and U.S. immigration controls.

"We can't let Putin win. I'll say it again. We can't let Putin win. It's in our overwhelming national interest and international interest of all our friends," Biden said, adding that other would-be aggressors will also be emboldened if the United States walks away from Ukraine.

Zelenskyy's visit to the White House will be his third since Russia invaded Ukraine in February 2022. While in Washington, he is also expected to meet with congressional leaders.

Zelenskyy was in Buenos Aires on Sunday for the inauguration of Javier Milei as Argentina's president.

Zelenskyy's office said he held talks with Milei, as well as the presidents of Ecuador, Paraguay and Uruguay, at a time when Ukraine is stepping up efforts to win more support from developing countries.

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