President Joe Biden's administration has allowed Ukraine to use US-made weapons to strike deep into Russia, two US officials and a source familiar with the decision said on Sunday, in a move that could widen the Ukraine-Russia war.
Ukraine plans to conduct its first long-range attacks in the coming days, the sources said, without revealing details due to operational security concerns.
The move comes two months before President-elect Donald Trump takes office on January 20 and follows months of pleas by Ukrainian President Volodymyr Zelenskiy to allow Ukraine's military to use US weapons to hit Russian military targets far from its border.
The change comes largely in response to Russia's deployment of North Korean ground troops to supplement its own forces, a development that has caused alarm in Washington and Kyiv, a US official and a source familiar with the decision said.
Zelenskiy said in his evening address that the missiles would "speak for themselves."
"Today, many in the media are saying that we have received permission to take appropriate actions," he said. "But strikes are not made with words. Such things are not announced."
The White House and US State Department declined to comment.
There was no immediate response from the Kremlin, which has warned that it would see a move to loosen the limits on Ukraine's use of US weapons as a major escalation.
Vladimir Dzhabarov, first deputy head of the Russian upper house's international affairs committee, said Washington's decision to let Kyiv strike deep into Russia could lead to "World War Three".
"The West has decided on such a level of escalation that it could end with the Ukrainian statehood in complete ruins by morning," Andrei Klishas, a senior member of the Federation Council, Russia's upper chamber of parliament, said on the Telegram messaging app.
Ukraine's first deep strikes are likely to be carried out using ATACMS rockets, which have a range of up to 190 miles (306 km), according to the sources.
While some US officials have expressed skepticism that allowing long-range strikes will change the war's overall trajectory, the decision could help Ukraine at a moment when Russian forces are making gains and possibly put Kyiv in a better negotiating position when and if ceasefire talks happen.
It is not clear if Trump will reverse Biden's decision when he takes office. Trump has long criticized the scale of US financial and military aid to Ukraine and has vowed to end the war quickly, without explaining how.
A Trump spokesperson did not immediately respond to a request for comment. But one of Trump's closest foreign policy advisers, Richard Grenell, criticized the decision.
"Escalating the wars before he leaves office," Grenell said, in an X post responding to the news.
Some congressional Republicans had urged Biden to loosen the rules on how Ukraine can use U.S.-provided weapons.
Since Trump's November 5 victory, senior Biden administration officials have repeatedly said they would use the remaining time to ensure Ukraine can fight effectively next year or negotiate peace with Russia from a "position of strength".
Russia is advancing at its fastest rate since 2022 despite taking heavy losses, and Ukraine said it had clashed with some North Korean troops deployed to Kursk.
Stretched by personnel shortages, Ukrainian forces have lost some of the ground they captured in an August incursion into Kursk that Zelenskiy said could serve as a bargaining chip.
"Removing targeting restrictions will allow the Ukrainians to stop fighting with one hand tied behind their back," Alex Plitsas, senior non-resident fellow at the Atlantic Council, said.
"However, like everything else, I believe history will say the decision came way too late. Just like the ATACMS, HIMARS, Bradley Fighting Vehicles, Abrams tanks and F-16. They were all needed much sooner," he added.
Despite Zelenskiy's pleas, the White House had been reluctant to allow U.S.-supplied weapons to be used to strike targets deep inside Russia for fear this could ratchet up the conflict.