(Bloomberg) -- The Bank of Japan said it would boost scheduled bond purchases as the intensifying Treasuries selloff puts upward pressure on global yields and weakens the yen.

The BOJ said it would buy 550 billion yen ($3.8 billion) of five-10 year bonds at its regular operations, up from 500 billion yen scheduled. The move comes as Japan’s benchmark 10-year yield hit 0.245%, approaching the 0.25% upper limit of the BOJ’s tolerated trading band. 

Japanese government bonds last came under pressure in June when only unprecedented BOJ buying kept benchmark yields below the 0.25% ceiling. BOJ Governor Haruhiko Kuroda has emphasized his determination to stick with rock-bottom interest rates even as global peers hike to tackle sky-high inflation.

Similar maturity Treasury yields have climbed above 3.3% -- underscoring a rate differential that’s driven the yen to a 24-year low. That has put FX traders also on alert for at least more verbal intervention from Japanese officials on the currency front.

“The increased amount is so small to raise doubt about its effectiveness but it does confirm the BOJ’s stance of capping 10-year yield at 0.25%,” said Makoto Suzuki, a senior bond strategist at Okasan Securities in Tokyo. “It has had no take-ups at the fixed-rate operations in July and August, so the BOJ has capacity to continue buying if yields face attacks to the upside.” 

But with Japanese inflation rising along with the global trend, it’s unlikely for JGB yields to fall much even with the BOJ’s help, Suzuki added. 

Some strategists have suggested a weaker yen would not be enough to influence policy.

“Kuroda has also said after the July meeting that it was unthinkable that the yen would stop weakening just by raising rates a bit, effectively removing any possibility of a policy tweak,” Katsutoshi Inadome, a strategist at Mitsubishi UFJ Morgan Stanley Securities in Tokyo, wrote in a note before the BOJ announcement. 

(Updates with additional comment)

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