Kremlin-linked military contractors have flown to Venezuela to provide security for Nicolas Maduro, reports say, as the president says he is willing to engage in talks with the opposition.

While the US intensified its push to drive the Venezuelan president from power, Russia has vowed to back its South American ally.

US secretary of state Mike Pompeo is set to brief the UN Security Council on 26 January after the US and a string of countries in the region said they recognised opposition leader Juan Guaido as the nation’s legitimate head of state and urged Mr Maduro to step down.

Russia opposed the US’s request to speak at the UN and instead accused Washington of engaging in a “destructive” foreign policy.

Private military contractors linked to Russia have flown into Venezuela in the past few days to beef up security for Mr Maduro, who has been in power since 2013, Reuters cited sources as saying.

Venezuela protests: thousands rally against government Show all 18 1 /18 Venezuela protests: thousands rally against government Venezuela protests: thousands rally against government Protesters clash with the Bolivarian National Police during a demonstration against the government of the Venezuela and president Nicolas Maduro in Caracas on 23 January 2019 EPA Venezuela protests: thousands rally against government Demonstrators cheer as Venezuela's National Assembly head Juan Guaido declares himself the country's "acting president" at a rally in Caracas AFP/Getty Images Venezuela protests: thousands rally against government Opposition supporters take part in a rally against Venezuelan President Nicolas Maduro's government REUTERS Venezuela protests: thousands rally against government Opposition supporters take part in a rally against Venezuelan President Nicolas Maduro's government in Caracas REUTERS Venezuela protests: thousands rally against government Juan Guaido, head of Venezuela's opposition-run congress, declares himself interim president of the nation until elections can be held during a rally in Caracas demanding leader Nicolas Maduro's resignation AP Venezuela protests: thousands rally against government Opposition supporters carry letters to form the word "Democracy" while taking part in a rally against Venezuelan President Nicolas Maduro's government REUTERS Venezuela protests: thousands rally against government Police watch over marching anti-government protesters in Caracas EPA Venezuela protests: thousands rally against government A vehicle is overturned as opposition demonstrators block a road during a protest against the Venezuelan government AFP/Getty Images Venezuela protests: thousands rally against government A National Police officer fires rubber bullets during a protest against Venezuelan President Nicolas Maduro's government in Caracas REUTERS Venezuela protests: thousands rally against government A demonstrator throws back a gas canister while clashing with security forces during a rally against Venezuelan President Nicolas Maduro's government in Caracas REUTERS Venezuela protests: thousands rally against government Security forces look on after clashing with opposition supporters participating in a rally against Venezuelan president Nicolas Maduro's government REUTERS Venezuela protests: thousands rally against government Demonstrators during a protest against the government of Nicolas Maduro at Plaza Altamira in Caracas Getty Images Venezuela protests: thousands rally against government Demonstrators during a protest against the government of Nicolas Maduro at Plaza Altamira in Caracas Getty Images Venezuela protests: thousands rally against government epa07313731 Opponents of Chavism demonstrate against the Government of President Nicolas Maduro in Caracas, Venezuela, 23 January 2019. Chavists and opponents are again demonstrating in the streets of the country to support or question the legitimacy of the head of state, which the Parliament and a large part of the international community do not recognize. EPA/CRISTIAN HERNANDEZ CRISTIAN HERNANDEZ EPA Venezuela protests: thousands rally against government Riot police clash with opposition demonstrators during a protest against the government of President Nicolas Maduro on the anniversary of the 1958 uprising that overthrew the military dictatorship, in Caracas on January 23, 2019. - Venezuela's National Assembly head Juan Guaido declared himself the country's "acting president" on Wednesday during a mass opposition rally against leader Nicolas Maduro. (Photo by YURI CORTEZ / AFP)YURI CORTEZ/AFP/Getty Images YURI CORTEZ AFP/Getty Images Venezuela protests: thousands rally against government The remains of a statue of Venezuela's late President Hugo Chavez is seen hanging from a pedestrian bridge after it was destroyed in San Felix, Venezuela REUTERS Venezuela protests: thousands rally against government Riot police on motorcycles clash with opposition demonstrators during protests in Caracas AFP/Getty Images Venezuela protests: thousands rally against government Supporters celebrate Juan Guaido declaration that he is Venezuelan president EPA

Mr Maduro held a news conference on Friday to defend the validity of his presidency and denounce Mr Guaido’s challenge.

He said the declaration was “a desperate act” backed by the US.

But he said that he would be willing to go to talks even if he “had to go naked”.

Earlier, US diplomats left their embassy in Caracas in a convoy of sport utility vehicles and with a police escort en route to the airport, according to a witness.

The state department ordered some US government workers to leave Venezuela and said US citizens there should consider leaving as well.

It did not immediately respond to a request for comment on the movement of embassy personnel.

Their departure came after Mr Maduro broke off relations with Washington and ordered the US personnel out.