US envoy meets American accused by Russia of spying

The US ambassador to Russia on Wednesday met an American ex-Marine accused of espionage whose detention has sparked the latest rift between the countries.

Ambassador Jon Huntsman met Paul Whelan at the Lefortovo prison in Moscow and afterwards spoke to his family by telephone, the US State Department said.

"Ambassador Huntsman expressed his support for Mr Whelan and offered the embassy's assistance," a State Department spokesperson said.

The United States has been cautious in its public comments on the case, with Secretary of State Mike Pompeo saying earlier Wednesday that Washington was trying to learn more about the situation.

"If the detention is not appropriate, we will demand his immediate return," Pompeo told reporters while on a visit to Brazil.

The consular visit took place five days after the 48-year-old Whelan was detained in Moscow. The Russian foreign ministry also confirmed that the United States was granted consular access.

Whelan faces up to 20 years in prison if found guilty, according to the ministry.

He was arrested "while carrying out an act of espionage", Russia's FSB domestic security service said.

His family has denied he is a spy, saying he was visiting Moscow to attend a wedding.

Born in Canada, Whelan is director of international security for BorgWarner, a car parts manufacturer headquartered near Detroit, his brother David Whelan has told several US media outlets.

His arrest came after President Vladimir Putin accused Western nations of using espionage cases to try to undermine an increasingly powerful Russia.

US intelligence services have accused Moscow of interfering in the 2016 presidential election.

US Special Counsel Robert Mueller has charged 25 Russians -- including members of the GRU military intelligence service -- and three Russian companies for that alleged interference, but they have not been arrested.

In December, Russian national Maria Butina pleaded guilty in a federal court in Washington to acting as an illegal foreign agent.

Butina faces up to six months in prison, followed by likely deportation.