NEW YORK, May 31 -- The U.S. dollar strengthened on Wednesday as the U.S. job openings data provided fresh optimism.

The dollar index, which measures the greenback against six major peers, increased 0.16 percent to 104.3344 in late trading.

Data released by the U.S. Bureau of Labor Statistics (BLS) on Wednesday showed that job openings in the United States reached 10.1 million in April, surpassing market expectations of 9.375 million and also higher than the revised figure of 9.745 million from the previous period.

The BLS report revealed a decrease in the number of people quitting their jobs by 286,000 to 5.7 million in April, while the number of hires remained relatively unchanged at 6.1 million.

As the tightness in the labor market has been one of the reasons cited by some Federal Reserve officials to advocate for further interest rate hikes, the job openings data provided fresh optimism for the U.S. dollar index.

In an interview with the Financial Times, Federal Reserve Bank of Cleveland President Loretta Mester said that she doesn't necessarily see a compelling reason for pausing rate increases amid a "really embedded, stubborn inflationary pressure."

However, the U.S. dollar narrowed its gains after the dovish comments from Federal Reserve Governor Philip Jefferson and Federal Reserve Bank of Philadelphia President Patrick Harker on Wednesday afternoon.

Moreover, the cooling down of inflation in Germany led to weakening of the euro.

Preliminary data from the German Federal Statistics Office showed Wednesday that the consumer price index - a measure of what consumers pay for goods and services - rose 6.1 percent year on year in May measured by national standards compared with a 7.2 percent rise in April.

In late New York trading, the euro decreased to 1.0673 dollars from 1.0719 dollars in the previous session, and the British pound rose to 1.2417 dollars from 1.2392 U.S. dollars in the previous session.

The U.S. dollar bought 139.3160 Japanese yen, lower than 139.8380 Japanese yen of the previous session. The U.S. dollar increased to 0.9115 Swiss francs from 0.9062 Swiss francs, and it decreased to 1.3576 Canadian dollars from 1.3602 Canadian dollars. The U.S. dollar was down to 10.8701 Swedish Krona from 10.8802 Swedish Krona.