Citing officials briefed on the matter, the Times said the United States determined months ago that a Russian military intelligence unit linked to assassination attempts in Europe had offered rewards for successful attacks last year.Islamist militants, or armed criminal elements closely associated with them, are believed to have collected some bounty money, the newspaper said.

The White House, the CIA and the Office of the Director of National Intelligence declined requests from Reuters for comment on the Times report.

President Donald Trump has been briefed on the intelligence finding, the Times said. It said the White House has yet to authorise any steps against Russia in response to the bounties.

Of the 20 Americans killed in combat in 2019, the Times said, it was not clear which deaths were under suspicion.

After nearly 20 years of fighting the Taliban, the United States is looking for a way to extricate itself from Afghanistan and to achieve peace between the US-backed government and the militant group, which controls swathes of the country.

On Feb 29, the United States and the Taliban struck a deal that called for a phased US troop withdrawal.

US troop strength in Afghanistan is down to nearly 8,600, well ahead of a schedule agreed with the Taliban, in part because of concerns about the spread of the coronavirus, US and NATO officials said in late May.

Russia denounces 'baseless, anonymous accusations'

Russia on Saturday denounced the newspaper report as “baseless” and dangerous.

The “baseless and anonymous accusations,” published by the newspaper, had “already led to direct threats to the life of employees of the Russian Embassies in Washington DC and London,” the Russian Embassy in Washington wrote on Twitter.

“Stop producing #fakenews that provoke life threats, @nytimes,” it added in a later tweet. 

Russia has a tortured history in Afghanistan, where the former Soviet Union in its final years was bogged down in a devastating fight against Islamist guerrillas, then backed by Washington.

But Russia has more recently been accused by the United States of quietly providing small arms to the Taliban.

According to the newspaper, the Taliban operation was led by a unit known as the GRU, which has been blamed in numerous international incidents including a 2018 chemical weapons attack in Britain that nearly killed Russian-born double agent Sergei Skripal.