Talks over the Transatlantic Trade and Investment Partnership (TTIP) have stalled, even though Washington and Brussels, which have been negotiating for three years, are still officially committed to sealing a deal before U.S. President Barack Obama leaves office in January.

"When listening to the American election campaign, you become really worried," Denmark's Prime Minister Lars Lokke Rasmussen told Reuters in an interview late Tuesday.

Serious doubts have surfaced over the deal, with thorny issues such as environmental and food standards as well as allowing foreign multinationals to challenge European government policies. In addition, looming elections in USA, France and Germany could hamper negotiations.

"Trump is the first republican presidential candidate, I can think of, who is actually against free trade," Rasmussen told the audience at a political rally Tuesday evening, pointing to Trump's ambition to "build walls and pull all jobs back to the United States."

"And Hillary Clinton is under great influence from Bernie Sanders, a left-wing socialist and also a protectionist," he said.

Small and export dependent Denmark, along with other Nordic countries like Sweden, have been some of the biggest supporters of the deal and have been worried the vote of Britain to leave the European Union had robbed them of a key free trade ally.

Rasmussen's comments come as EU leaders prepare for a summit on Sept. 16 in Bratislava -- without Britain -- which is looking at how to draw up a post-Brexit future for the Union.

French Trade Minister Matthias Fekl said last week he favoured calling a halt to the talks. And while German Chancellor Angela Merkel still backs the talks, German Economy Minister Sigmar Gabriel called them "de facto dead".

"While we all very recently thought we should clinch a new trade deal that could bring wealth to both USA and Europe, there's now no telling where it will end," Rasmussen said in the interview, expressing concerns over the latest messages from France.

"This just underscores the point that it would be good to reach a deal this year. I think President Obama has a commitment to this issue that I would like to see materializing into at least a political deal," he said.

Sweden is working with Finland, Spain and Italy to keep a deal alive, the country's EU minister Ann Linde said Monday. She however acknowledged that sharper political rethoric along with Britain's decision in June to leave the European Union could put negotiations on ice for the foreseeable future.

The United States is Denmark's third-largest export market and the EU's single largest export market.

(Reporting by Jacob Gronholt-Pedersen)

By Jacob Gronholt-Pedersen