Spain, Germany, France and the UK have warned Venezuelan President Nicolás Maduro that he must call elections within eight days – or they will officially recognise the opposition.
Mr Maduro is under pressure after his rival Juan Guaidó declared himself “acting president” on Wednesday.
Several countries, including the US, already back Mr Guaidó as president.
But Mr Maduro has major allies too, and divisions between world powers were laid bare at the UN on Saturday.
President Maduro was sworn in for a second term earlier this month, in an election marred by an opposition boycott and allegations of vote-rigging, leading to large anti-Maduro protests.
He accuses Mr Guaidó, the head of the National Assembly, of mounting a coup.
On Saturday, Spanish Prime Minister Pedro Sanchez wrote on Twitter: “Spain has a responsibility to Latin America… we do not seek to change or remove governments, we want democracy and free elections in Venezuela.”
France and Germany also issued similar statements, in what looked like a co-ordinated demand that elections be held in Venezuela.
UK Foreign Secretary Jeremy Hunt said the election in Venezuela had been “deeply flawed”, repeating his view that Mr Maduro was “not the legitimate leader”.
Russia, a UN Security Council member, has said foreign support for Mr Guaidó violates international law and is a “direct path to bloodshed”. China, Mexico and Turkey have also publicly backed Mr Maduro.
What happened at the UN?
Discussions at the UN Security Council meeting in New York on Saturday were tense as nations clashed on how to resolve the crisis in Venezuela.
US Secretary of State Mike Pompeo accused Russia and China of “propping up a failed regime” and said it was time to “support the Venezuelan people immediately”.
“No more delays, no more games. Either you stand with the forces of freedom, or you’re in league with Maduro and his mayhem,” he said.
But Russia’s UN ambassador, Vassily Nebenzia, accused Washington of plotting a coup against Mr Maduro.
He said the council was not established to “support regime change” and called for further dialogue to “find a way forward”.
China’s representative to the UN, Ma Zhaoxu, said that while his country was committed to the “purposes and principles” of the council, the situation in Venezuela “does not constitute a threat to national security” and China “does not interfere in other countries’ internal affairs”.
Why is Maduro being challenged?
He was re-elected to a second term last year – but the elections were controversial, with many opposition candidates barred from running or jailed.
The National Assembly argues that the presidential position is actually vacant because the election was unfair – and that under the constitution this means that Mr Guaidó, as head of the National Assembly, should take over as acting president instead.
Tens of thousands have held protests over Venezuela’s economic crisis – including an annual inflation rate that the opposition says reached 1,300,000% last year.
Mr Maduro has so far retained the support of the country’s military, but Mr Guaidó has asked them to “put themselves on the side of the Venezuelan people” and back him instead.