The dollar index, which measures the greenback against six major peers, was up 0.40 percent at 93.4450 in late trading.
Sterling dropped as traders worried about uncertainty around Brexit.
Crucial talks aimed at finding a post-Brexit trade deal between Britain and the European Union (EU) opened Tuesday in London.
British Prime Minister Boris Johnson said Monday that he wants a post-Brexit trade deal agreed with the EU by an Oct. 15 deadline, warning that a failure of that could mean London ending its EU membership with no deal.
In late New York trading on Tuesday, the euro was down to 1.1780 U.S. dollars from 1.1811 dollars in the previous session, and the British pound fell to 1.2990 dollars from 1.3168 U.S. dollars in the previous session. The Australian dollar decreased to 0.7215 U.S. dollar from 0.7276 dollar.
The U.S. dollar bought 106.03 Japanese yen, lower than 106.28 Japanese yen of the previous session. The U.S. dollar was up to 0.9173 Swiss franc from 0.9162 Swiss franc, and it increased to 1.3222 Canadian dollars from 1.3094 Canadian dollars.