US President Joe Biden brushed off a threat from Russian leader Vladimir Putin about war against the West if Ukraine’s allies allow it to use weapons deeper inside Russia. It is a shift that Kyiv has pleaded for, but no decision was immediately announced following a meeting on Friday between Biden and Britain’s prime minister.

Ukraine and many of its supporters in the US and Europe want Biden to lift restrictions on Western-provided long-range weapons, and there are signs Biden might shift the administration’s policy.

The US, concerned about any step that could lead Russia to escalate the conflict, has moved cautiously before granting a series of earlier requests from Ukraine for specific arms, including advanced tanks, missiles and rocket systems, and F-16 fighter aircraft. Russian officials have issued similar threats before many of those past decisions.

Ukraine was a key topic for Biden and British Prime Minister Keir Starmer after this week’s visit to Kyiv by their top diplomats, who came under fresh pressure to loosen weapons restrictions. So far, the US has allowed Ukraine to use American-provided weapons only in a limited area inside Russia’s border with Ukraine.

Two US officials familiar with discussions said they believed Starmer was seeking Biden’s approval to allow Ukraine to use British Storm Shadow missiles for expanded strikes in Russia.