Russia has promised to respond to the expulsion of 35 of its diplomats from Washington, amid a bitter dispute over alleged Russian interference in the recent US presidential election.

A spokesman for President Vladimir Putin said the Kremlin's reaction would cause the US "significant discomfort".

However, he hinted that Russia may wait until Donald Trump, who has played down the hacking claims, becomes president.

Russia has denied any involvement and called the US sanctions "ungrounded".

On Thursday, the US state department declared the 35 Russian diplomats from the Washington embassy and the consulate in San Francisco "persona non grata", and gave them and their families 72 hours to leave the US.

Sanctions have also been announced against nine entities and individuals including two Russian intelligence agencies, the GRU and the FSB.

And the US will close two compounds - in New York and Maryland - used by Russian intelligence services.

President Barack Obama had vowed action against Russia amid US accusations that it directed cyber-attacks against the Democratic Party and Hillary Clinton's campaign.

Reacting to the announcement, Kremlin spokesman Dmitry Peskov said: "Undoubtedly, commensurate reaction based on the principle of reciprocity will cause significant discomfort to the American side in the same areas."

But he added that Russia would not act "in haste" and alluded to the upcoming change at the helm of the US.

"These decisions were taken by President Obama, but Trump will become the head of state in three weeks' time," Mr Peskov said. "Of course, this factor will certainly be taken into account one way or another."

'A decade-long campaign'

Separately, the Russian embassy to the UK tweeted a visual gag calling the Obama presidency a lame duck.

President-elect Trump has dismissed the hacking claims as "ridiculous" and said Americans should "get on with our lives" when asked about the possibility of sanctions before the announcement.

Emails stolen from Hillary Clinton's campaign manager and from the servers of the Democratic National Committee - some containing embarrassing information for Democrats - were released during the election campaign through the Wikileaks website.

US intelligence agencies, including the FBI and CIA, have concluded that the aim of the hack was to cause damage to Mrs Clinton and the Democrats and favour Mr Trump.