Venezuela’s opposition leader has told the BBC that people are living in a “dictatorship”, and renewed his calls for fresh elections.
Juan Guaidó declared himself interim leader last week and has been recognised by more than 20 countries, including the US.
President Nicolás Maduro retains the support of Russia, which has accused the US of “illegal” interference.
At least 40 people are believed to have died in recent unrest, the UN says.
Protests have been growing since Mr Maduro began a second term as president this month. He was elected last year during a controversial vote in which many opposition candidates were barred from running or jailed.
Venezuela has been struggling with a massive economic crisis. Hyperinflation and shortages of essentials such as food and medicine have forced millions to flee the nation.
What has Mr Guaidó been saying?
Speaking to BBC Mundo in Caracas on Monday, he defended his claim to be interim leader.
Mr Guaidó said the Venezuelan constitution allowed him, as the head of the National Assembly, to take power when the president was considered to be illegitimate.
“My duty is to call for free elections because there is an abuse of power and we live in a dictatorship,” Mr Guaidó said.
He added: “In Venezuela, we either accept domination, total oppression and torture… from Maduro’s regime or we choose freedom, democracy and prosperity for our people.”
Mr Guaidó said the Maduro administration was “killing young poor people” in the streets.
He has pledged to act as interim leader to oversee fresh elections. However, his declaration of leadership has divided the international community.
Mr Guaidó has called for further demonstrations this week, after tens of thousands came out to protest against Mr Maduro last Wednesday.
What is the latest in the diplomatic row?
Russia renewed its criticism of what it calls US interference on Tuesday.
It came after US National Security Adviser John Bolton announced sanctions against Venezuela’s state-owned oil firm PDVSA.
Mr Bolton said the move was to ensure President Maduro and his allies could “no longer loot the assets of the Venezuelan people”. He again appealed to the military to switch allegiance to Mr Guaidó
Sergei Lavrov, Russia’s foreign minister, sharply criticised the sanctions, which he said violated “all possible international norms” in pursuit of regime change.
Mr Lavrov also “pledged to do everything to support the legitimate government of President Maduro”, during a news conference on Tuesday.
The Russian ministry of finance said on Tuesday that it expected Venezuela to keep up debt repayments it owed, despite the ongoing crisis.
In New York, US deputy ambassador to the UN Cynthia Plath said her country was “committed to holding accountable those responsible for Venezuela’s tragic decline”.
Venezuelan ambassador Jorge Valero responded by accusing the US administration of preparing a “military invasion”. Ms Plath walked out of the room during his comments, before returning.
Who supports whom?
Venezuela broke off relations with the US last week in response to its recognition of Mr Guaidó as interim leader and ordered all US diplomats to leave the country.
More than 20 countries have followed the US in recognising Mr Guaidó as interim president.
Russia, China, Mexico and Turkey are among those who have publicly backed Mr Maduro.
On Saturday, several European countries including Spain, Germany, France and the UK said they would recognise Mr Guaidó as president if elections were not called within eight days.
What are the UN’s casualty figures?
The estimated death toll of 40 includes 26 people shot dead by pro-government forces, five killed in house raids and 11 during looting, UN human rights spokesman Rupert Colville said on Tuesday.
Another 850 people have reportedly been detained since 21 January – including dozens of children as young as 12.