Russia-Ukraine updates: 2 US veterans who joined Ukrainian forces missing

Nearly 28,000 Ukrainian citizens have arrived in Belarus since Russia invaded neighboring Ukraine on Feb. 24, according to the Belarusian State Border Committee.

"Between 6 a.m. on February 24 and 6 a.m. on May 20, a total of 27,868 Ukrainian citizens arrived in Belarus, including 15,793 who crossed the Ukrainian-Belarusian border, 10,563 by transit through Poland, 1,305 through Lithuania, and 207 through Latvia," the committee said in a statement Friday.

In the past 24 hours alone, 154 Ukrainian citizens arrived in Belarus, including 120 via Poland, according to the committee.

Belarus shares a land border with both Ukraine and Russia, and is Moscow's main ally.

President Joe Biden will sign the $40 billion Ukraine aid bill while he's in Asia, a White House official said.

"The president does intend to sign the bill while he's on the road so that he can sign it expeditiously," national security adviser Jake Sullivan told reporters aboard Air Force One while en route to the region Thursday evening. "The modalities of that are being worked right now so that he can get it and sign it."

The bill, which passed the Senate earlier Thursday with bipartisan support, will need to be flown to the region so that Biden can sign it. The practice of flying bills to presidents for signature dates back to the Truman administration, but this is a first for Biden.

Biden departed for South Korea Thursday and will visit Japan later in the week during his first trip to Asia as president.

-ABC News' Sarah Kolinovsky

U.S. Secretary of State Antony Blinken announced Thursday that he has authorized a 10th drawdown of additional arms and equipment for Ukraine worth $100 million from U.S. Department of Defense inventories.

This brings total U.S. military assistance to Ukraine to approximately $3.9 billion in arms and equipment since Russia invaded Ukraine on Feb. 24.

"The United States is committed to helping Ukraine continue to meet its defense needs and build its future capabilities, as well as to bolster Allies and partners across NATO’s Eastern Flank and the broader region," Blinken said in a statement.

-ABC News' Shannon Crawford

The Senate voted on Thursday to pass an additional $40 billion in new military and economic aid for Ukraine after President Joe Biden called on Congress for more funding.

The bill received bipartisan support, passing with a vote of 86-11.

The House passed the aid package earlier this month, which is now headed to Biden's desk for signing.

"By passing this aid package the Senate can now say to the Ukrainian people help is on the way: real help, significant help, help that could ensure the Ukrainian people are victorious," Majority Leader Chuck Schumer said during his floor remarks before the vote.

-ABC News' Allison Pecorin