MOSCOW, Dec 30 — Russian President Vladimir Putin, in a New Year letter to his US counterpart Donald Trump, said today that Moscow was ready for dialogue on a "wide-ranging agenda", the Kremlin said.

At the end of November, Trump abruptly cancelled a planned meeting with Putin on the sidelines of a G20 summit in Argentina, citing tensions about Russian forces opening fire on Ukrainian navy boats and then seizing them.

"Vladimir Putin stressed that the (Russia - United States) relations are the most important factor for providing strategic stability and international security," a Kremlin statement said.

"He confirmed that Russia is open for dialogue with the USA on the most wide-ranging agenda."

In a separate letter to Syrian President Bashar al-Assad, Putin pledged continuation of aid to the Syrian government and people in the "fight against terrorism, in defence of state sovereignty and territorial integrity".

Putin also sent New Year greetings to other world leaders including prime ministers Theresa May of Britain and Shinzo Abe of Japan, as well as Chinese President Xi Jinping.

Putin wished "well-being and prosperity to the British people", the Kremlin said.

Russia's embassy in London said on Friday Moscow and London had agreed to return some staff to their respective embassies after they expelled dozens of diplomats early this year.

Britain expelled 23 Russian diplomats over accusations the Kremlin was behind a nerve toxin attack in March on former double agent Sergei Skripal and his daughter in the English city of Salisbury.

Russia, which denies any involvement in the poisoning, sent home the same number of British embassy workers in retaliation. — Reuters