The dollar index, which tracks the greenback against six major rival currencies, was up 0.21 percent to 93.632, after rising as high as 93.876.

The Labor Department said on Tuesday that job openings, a measure of labour demand, increased 461,000 to a seasonally adjusted 6.2 million, the highest since the series started in December 2000. [nL1N1KU0KW]

"The JOLTS numbers were certainly the latest metric to highlight tightening labour market conditions in the U.S. and to that extent that's certainly dollar-positive data," said Omer Esiner, chief market analyst at Commonwealth Foreign Exchange in Washington.

"The move in the dollar was probably exacerbated by the light summertime trading volumes in an otherwise quiet economic calendar for most of this week."

The data reinforces the strong nonfarm payrolls data from Friday, said Minh Trang, senior currency trader at Silicon Valley Bank in Santa Clara, California.

The greenback, which has weakened since the start of the year, got a boost on Friday after a strong U.S. July payrolls report bolstered the case for the Federal Reserve to further tighten monetary policy.

Tuesday's strong job openings data helped the dollar shake off some the weakness it experienced on Monday following dovish comments from St. Louis Fed President James Bullard and Minneapolis Fed President Neel Kashkari.

The greenback added to losses against the yen after U.S. President Donald Trump on Tuesday warned North Korea it would be met with "fire and fury" if it threatens the United States.

Earlier Pyongyang said it was ready to give Washington a "severe lesson" with its strategic nuclear force in response to any U.S. military action. The dollar was down 0.35 percent against the yen at 110.34 yen.

The euro was down 0.39 percent to $1.1747, but not far from last week's 2-1/2-year high of $1.1909.

The European Central Bank is widely expected to scale back its quantitative easing programme as doubts rise about whether the Fed will be able to raise rates again this year, which has boosted the euro.

Sterling hit a 10-month low against the euro as investors grew more bearish about Britain's economic outlook after consumer spending fell for a third month in a row in July.

(Reporting by Saqib Iqbal Ahmed; Editing by Chizu Nomiyama and Chris Reese)

By Saqib Iqbal Ahmed