The Bank of Japan has reiterated its strong commitment to ultraloose monetary policy with four days of unscheduled bond buying as the widening interest rate gap with the United States puts upward pressure on bond yields and weakens the yen.

The move comes as Japan’s benchmark 10-year yield stayed elevated at the 0.25% upper limit of the BOJ’s tolerated trading band despite announcing unlimited bond purchases for the first time since late March. Similar maturity Treasury yields hovered just below 3% — underscoring a rate differential that’s driven the yen to a 20-year low.

"The BOJ is demonstrating that its stimulus resolve hasn’t shifted even with the yen weakening rapidly,” said Tomo Kinoshita, global market strategist at Invesco Asset Management. The bank won’t follow its peers in tightening policy while the economy is fragile and inflation is being fueled by cost pressures rather than demand, he added.