US President Donald Trump is weighing on a recommendation from his National Security Council to expel a group of Russian diplomats from Washington in response to the poisonings of a former Russian spy and his daughter in Britain, the media reported. France and Germany backed Mrs May's call for tougher action, though their exact plans are less clear.
The leaked proposal to expel Russian diplomats, first reported by CNN, raised questions about whether people inside the US government disclosed the pending action to force the president's hand in taking tough action against Moscow.
A number of European countries are expected to take further steps to punish Moscow on Monday, with the Czech Republic, Lithuania, Denmark and Ireland considering expelling Russian diplomats.
The diplomats in question are considered undercover spies who disguise as embassy staff to carry out intelligence activity, one of the aides cited by Bloomberg said.
Trump allegedly discussed the issue on Friday with the U.S. Ambassador to Russia Jon Huntsman, Attorney General Jeff Sessions, Defense Secretary James Mattis and National Security Adviser H.R. McMaster, among others.
Last week, European Union leaders promised an "unprecedented" diplomatic response to the attack. There is no Russian ambassador in Ukraine for a long time, we did not accept agreement for a new ambassador, as there is no Ukrainian ambassador to Russia.
Russian President Vladimir Putin described the accusations as "delirium" on Sunday, in comments after winning another six years as president.
Meanwhile, Russian spokesman Dmitry Peskov denied rumors that Skripal had sent a letter to Putin asking him to be allowed to return to Russia.
Russia and the United Kingdom have been embroiled in a bitter diplomatic fight since Russian former double agent Sergei Skripal, 66, and his daughter, 33-year-old Yulia Skripal, were poisoned in the English cathedral city of Salisbury on March 4.
The White House's National Security Council recommended the expulsions after 10 European nations swung behind the United Kingdom in condemning the apparent attempted murder in strong terms, according to CNN.
Congress has pressured Trump to get tougher on Putin and passed legislation in August giving lawmakers the power to block the president from lifting punitive USA measures imposed after Russia's incursion into Ukraine.
Russian President Vladimir Putin at the Kremlin in Moscow, Russia March 19, 2018.
A national defense strategy assembled by the Pentagon under Mattis and publicly summarized in January described China and Russian Federation as the top global adversaries of the U.S. Earlier this month, the administration slapped financial sanctions against a St. Petersburg-based internet "troll farm" and its alleged owner - a close Putin ally - whom Mueller indicted over a covert social media campaign to influence the 2016 election.