Gordon Brown has described Joe Biden as a “friend of Britain” and believes the president-elect could visit the UK in the next six months.
The former Prime Minister, who has worked with Mr Biden, added that he did not believes a US-UK trade deal would happen “immediately” but that it could be realistic option “over time”.
When asked whether it mattered that some of Mr Biden’s senior people did not like Prime Minister Boris Johnson, Mr Brown said: “Joe Biden has always been a great friend of Great Britain.
“I think he wants to be a friend of Britain. I think he plans, from what I know, to come to Britain within the first six months of becoming president, probably to the G7.”
He added: “He would prefer us to be in the European Union, I know that. He is also worried about the Good Friday Agreement – he is not going to allow a trade deal with Britain to happen if we in some way breach the Good Friday Agreement.”
Prime Minister Boris Johnson is still waiting on a call with the president-elect as reports suggested the ex-senator would not treat a trade deal with the UK as a priority.
Mr Brown also said Mr Biden will seek international co-operation on global health, the economy and the “green revolution” as he works with other nations.
Speaking on BBC Radio 4’s Today programme on Monday, he said: “I think there are three big issues apart from security and Nato.
“The first is co-operation on global health, finding a vaccine, treatments, therapeutics, sharing information.
“I think the second is co-operation on the economy. I believe we need a co-ordinated fiscal and monetary package to get the world economy moving forward again and I think that’s what Joe Biden will want.
“While he has huge domestic issues and there are huge divisions in America he has to sort out, there’s a third issue and I think that’s the green revolution, and I expect him to be leading with other countries in trying to sort out climate change policy in the future.”
Mr Brown said that Mr Biden will be able to do a huge amount by executive order, but if anyone can get legislation through it is him.
Describing him as a “natural negotiator”, he added: “If Ronald Reagan was the great communicator, he is the great conciliator and he is capable of bringing people together.”
Mr Biden clinched victory after winning the key battleground of Pennsylvania on Saturday, some four days after polls closed, pushing him over the 270 electoral college votes threshold.