The head of the mission sent by the main European security and rights organisation to monitor the US presidential election said Donald Trump's advisers must make clear to him he has lost in the likely event that this result is confirmed.
German politician Michael Link told the Funke newspaper group that Trump's allegations of fraud and cheating in the vote-counting process were unfounded and risked undermining confidence in the US democratic system.
Trump, 74, has been defiant as his chances fade for securing a second four-year term. He has made repeated and unfounded claims of electoral fraud, while his campaign pursues lawsuits that legal experts say are unlikely to alter the election outcome.
"The American President has a great responsibility for preserving calm in the US," Link was quoted as saying. "I'm not sure this is clear to him."
He added: "I can only hope that Trump has well-intentioned advisers who will tell him if he has lost. All indications are that that is the result which we will soon see."
Link leads the mission of the Organisation for Security and Cooperation in Europe (OSCE), of which the US is a founder member, which has for decades sent delegations to monitor the probity of elections around the world.