The U.S. dollar index, which measures the greenback's strength against a trade-weighted basket of six major currencies, was little changed at 96.53, close to Tuesday's seven-month low of 96.47. The pan-European Stoxx Europe 600 index slipped 0.1 percent.
The Dow Jones Industrial Average rose 41.32 points, or 0.2 percent, to 21,177.55, the S&P 500 gained 3.35 points, or 0.14 percent, to 2,432.68 and the Nasdaq Composite added 14.78 points, or 0.24 percent, to 6,289.84.
Comey's evidence comes as Britain votes in a snap election, with Prime Minister Theresa May's seemingly insurmountable lead slashed, fuelling fears the country could be thrown into fresh uncertainty and making talks on leaving the European Union much harder. Those talks begin later this month. A lower-than-expected addition to the non-farm jobs in the United States led to a sharp rise in the shared currency with respect to the U.S. dollar. Consumer-price growth climbed as high as 2 percent in February, stoking calls in nations such as Germany to end bond purchases and start raising interest rates, but slowed to 1.4 percent in May and missed economists' forecasts. That view, of course, has been tested by recent polls, which predicted outcomes ranging from a majority for the Conservatives to a "hung" parliament.
According to the latest Survation poll conducted on Friday and Saturday, British Prime Minister Theresa May's lead over the opposition Labour Party has shrunk from 17 to just 1 percentage point.
If they do revise down the inflation outlook, "the risk is that a tapering announcement will be delayed to October or even December, before all criteria are met", said Frederik Ducrozet, an economist at Banque Pictet & Cie in Geneva.More news: Health care on Senate Republicans' Agenda
The move was seen as a mild unwinding of the safety play that had boosted the Japanese currency earlier this week. The dollar hit a six-week low versus the yen as investors adopted a cautious stance ahead of general elections in Britain, a European Central Bank meeting and a testimony by former FBI Director James Comey in the United States - all scheduled for Thursday. The panel is investigating Russian efforts to interfere in last year's presidential race.
The single currency had recovered nearly 10 percent against the dollar in the past five months, benefiting from broad greenback weakness but also on the view that rising inflation would prompt the European Central Bank to raise interest rates in early 2018.