The euro and the British pound were down against the dollar on Thursday, due to a return of risk aversion in financial markets fueled by political uncertainty in the United States and the health crisis in Europe.

Around 19:00 GMT (21:00 in Paris), the euro fell 0.38% against the dollar, to 1.1816 dollar, and the pound fell 0.56%, to 1.3075 dollar.

The dollar index, which measures the U.S. currency against a basket of other currencies, rose 0.36 percent.

"The greenback has recovered from multi-week lows as caution has strengthened in the market," said Joe Manimbo of Western Union.

Among the concerns, the expert evokes in particular "the gloomy prospects about the recovery plan in the United States."

Negotiations between Democrats and Republicans have been at an impasse for three months and less than two weeks before the presidential election an agreement seems increasingly unlikely.

The Democratic Speaker of the House of Representatives, Nancy Pelosi, was nevertheless optimistic Thursday morning, assuring that "both sides want a deal".

The decline in the number of unemployed people receiving benefits in the United States, according to weekly figures from the Department of Labor, has not particularly reassured market participants.

Some experts downplayed this decline, believing that it was partly due to the fact that many beneficiaries had reached the end of their entitlement.

"Markets have also been affected by another negative factor, namely the unprecedented rise in coronavirus cases in Europe," Manimbo said.

In France, 41,622 new cases of Covid-19 were recorded in 24 hours, 15,000 more than the day before, a new record.

The pound, for its part, remained suspended in the bitter post-Brexit trade negotiations.

After a week of deadlock, the United Kingdom and the European Union resumed their discussions on Thursday in London with important differences to be filled and very little time to escape the "no deal".