Top-level US-China trade talks are scheduled to resume next Thursday and Friday, when Chinese Vice Premier Liu He meets with US Trade Representative Robert Lighthizer and Treasury Secretary Steven Mnuchin in Washington.
"The tone of markets overall has softened again today following news that Chinese officials are reluctant to agree to a broad trade agreement with the US," Shaun Osborne, chief market strategist, at Scotiabank in Toronto, said in a note.
The dollar index, which measures the greenback against a basket of other currencies, was down 0.02% at 98.792.
Renewed concerns over the trade war pressured trade-oriented currencies such as the Australian dollar, which slipped 0.34% against the greenback.
Investors also awaited the US Federal Open Market Committee's minutes from its September meeting, due on Wednesday, for clues to whether the Fed will cut rates at its October meeting, its third interest rate cut for the year.
The greenback hit a 28-month high against the euro early last week. On Monday, the common currency was up 0.14% at $1.0991.
Sterling edged lower against the greenback as investors grew increasingly concerned that Britain and the European Union were no closer to agreeing a Brexit withdrawal deal. The pound was 0.06% lower on the day.