LONDON (AP) — British counterterrorism police arrested three men in London on Thursday on suspicion of spying for Russia.

The suspects, men aged 44, 45, and 48, were arrested by the Metropolitan police at addresses in central and west London. Searches at the addresses are ongoing.

Britain on Friday called for a raft of measures against Russia to strengthen Ukraine's hand ahead of any future peace talks, as Ukrainian President Volodymyr Zelenskiy heads to London for discussions with key allies.

European leaders vowed to work in coordination to ratchet up the pressure on Russia as the so-called “coalition of the willing” met in London to discuss strategies to end the war in Ukraine.

British authorities on Thursday arrested three men suspected of spying for Russia, according to London's Metropolitan Police.

Russia is reinforcing its presence at a base in the Arctic Circle, including nuclear weapons pointed towards the United States, according to Norwegian Defense Minister Tore Sandvik.