The Fed Chairwoman Janet Yellen said in a speech in New York on Thursday that the U.S. economy continued to progress and the U.S. labour market continued to strengthen. She also said that there were signs of the accelerating in inflation, adding that low inflation, which was driven by the strong U.S. dollar and low oil prices, was temporary.

The Fed chairwoman noted that the global growth remained weak.

Yellen pointed out that the Fed remained on track for further interest rate hikes, saying that the decision to raise the interest rate in December was the right decision.

"We remain on a reasonable path and I don't think December was a mistake," the Fed chairwoman said. She added that further interest rate hikes should be gradual.

Yellen noted that the U.S. economy was not a bubble economy.