President Trump is considering authorizing fresh funding for Ukraine for the first time since he took office in January, multiple diplomatic sources told CBS News.

The sources indicated the new funding could be intended to send a message to Russia, which has pounded Ukraine with drone and missile attacks in recent days. Russia this week launched what Ukraine described as the largest drone attack since its full-scale invasion began in February 2022 — the latest in a wave of aerial assaults that have pummeled Kyiv and other cities. 

Mr. Trump hinted earlier this week that he planned to send Ukraine more defensive weapons. Just days earlier, his administration paused some arms shipments — a move one White House official cast as one part of a wider global review of weapons transfers. 

The source of the possible new funding for Ukraine is unclear. But U.S. officials told CBS News Mr. Trump has $3.85 billion in leftover Biden-era presidential drawdown authority sitting at his fingertips, which could be used to send American military equipment to Ukraine. Former officials also told CBS News the president has the authority to seize around $5 billion in foreign Russian assets and direct the funds to Ukraine, though neither he, nor former President Joe Biden have used that power.

CBS News has reached out to the White House for comment.

The U.S. has sent tens of billions of dollars in military aid to Ukraine since early 2022. Mr. Trump has previously been critical of that spending, and has pressed Ukraine and Russia to work toward a peace agreement — periodically lashing out at both countries.

In recent days, Russia has drawn the president's ire. He told reporters last week he was "very disappointed" with a call with Russian President Vladimir Putin, and he later suggested that Russia's strikes on Ukraine could prompt him to send more arms to Ukraine.

"Putin is not treating human beings right. He's killing too many people," Mr. Trump told reporters during a Cabinet meeting Tuesday. "So we're sending some defensive weapons to Ukraine, and I've approved that."

At other points, Mr. Trump has attacked Ukrainian President Volodymyr Zelenskyy. A February Oval Office meeting with the Ukrainian leader descended into a verbal argument, leading to a brief pause on U.S. aid, and Mr. Trump has accused Zelenskyy of prolonging the war. 

Trump says "NATO is paying" for Ukraine aid

Meanwhile, Mr. Trump has pushed European countries to take on a larger share of the burden of supporting Ukraine. 

NATO told CBS News on Friday it was working with member states to "urgently" move U.S.-made ammunition and air defenses to Ukraine, but declined to explain if any new mechanism had been established to do so. A day earlier, Mr. Trump spoke with NATO Secretary-General Mark Rutte to discuss European partners purchasing U.S.-made equipment, according to diplomatic sources.

U.S. law requires countries to seek approval before transferring any American-made equipment to a third party such as Ukraine. Under both Mr. Trump and Biden, the federal government has approved transfers by other countries to Ukraine.

In an interview with NBC News on Thursday, Mr. Trump suggested NATO would buy weapons from the U.S. to transfer to Ukraine. That would mark a dramatic shift in policy since, in the past, NATO as an institution has not directly armed non-member state Ukraine. Instead, individual members of the alliance have chosen to assist Ukraine on their own.

"We're sending weapons to NATO, and NATO is paying for those weapons, 100%," Mr. Trump told NBC News' Kristen Welker.

When asked about the NATO plan during a press availability in Malaysia on Friday, Secretary of State Marco Rubio declined to detail any new mechanism and referred to plans for European countries to buy weapons.

"At the end of the day, some of the systems that Ukraine requires are systems that Europe doesn't make. They would have to purchase them from the United States," Rubio said.