Europe's top diplomat has appealed for calm ahead of negotiations on Britain’s exit from the European Union.

European Council president Donald Tusk has said Brexit negotiations will become "impossible" if emotions are allowed to run unchecked.

It comes after British Prime Minister Theresa May claimed European officials were trying to influence the result of the general election in the UK.

In a statement read out after a meeting with Norwegian Prime Minister Erna Solberg, Mr Tusk said it will take moderation, mutual respect and a maximum amount of goodwill to make the divorce discussions a success.

"These negotiations are difficult enough as they are,” he said. “If we start arguing before they even begin, they will become impossible."

"The stakes are too high to let our emotions get out of hand. Because at stake are the daily lives and interests of millions of people on both sides of the Channel."

In an address from Downing Street on Wednesday, Mrs May said "there are some in Brussels who do not want these talks to succeed, who do not want Britain to prosper."

Mrs May's claims followed a German newspaper's damning account of a dinner last week between the PM and European Commission president Jean-Claude Juncker.

Mr Junker reportedly called German Chancellor Angela Merkel after the meeting to say Mrs May is on a "different galaxy" over the negotiations.

Mrs May dismissed the claims as "Brussels gossip."

The Norwegian Prime Minister told Sky News the people of Europe and the UK would suffer if politicians could not work together.

Mrs Solberg said: "For the benefit of the whole of Europe we need to find workable solutions for the competitiveness of the whole continent.”

"It's European people who will lose out on possibilities and economic development if you can't find good working relationships."