"The BOJ will continue to take steps to ensure the yield curve remains in the shape needed to meet our 2 pc inflation target," Kuroda said, while refraining from commenting on foreign exchange rates

The dollar was last up 0.5pc at 110.67 yen after rising to 110.78, its loftiest perch since June 1. It was up 3.7pc for the week.

"The BOJ is taking steps to build up its credibility. It's not just rhetoric, or verbal intervention. Besides going to negative rates, they're actually participating in implementing steps in the direction that they want to go in," said Bart Wakabayashi, Head of Hong Kong FX Sales at State Street Global Markets.

Japanese Finance Minister Taro Aso said that while nervous moves were seen in the forex market, the underlying moves were stabilising.

Thursday's U.S. data gave even more credence to rate-hike bets. Housing starts marked a nine-year peak last month, weekly jobless claims fell to a 43-year low and consumer prices posted their biggest increase in six months.

The data pushed up yields on US Treasury notes, underpinning the dollar. Yields have been on an uptrend since last week's USelection, amid speculation that the administration of President-elect Donald Trump will embark on inflationary policies.

"Everybody wants to buy the dollar on dips, and is waiting for dips, but there is no dip," said Kaneo Ogino, director at foreign exchange research firm Global-info Co in Tokyo. "The Trump rally can continue, unless some cautious comments come out from the U.S. side."

While Yellen did not explicitly say the Fed would take action at its Dec. 13-14 policy meeting, she told a Congressional committee that a rate hike was likely "relatively soon."