BEIJING (AP) — China’s government has promised not to weaken its currency to boost exports and rejected U.S. concern about the sagging yuan as groundless and irresponsible.

A foreign ministry spokesman, Lu Kang, said Tuesday that Beijing has no intention of using “competitive devaluation” to make exports less expensive during a tariff fight with Washington.

A U.S. official told reporters in Washington the Trump administration is concerned about the weakening yuan.

The tightly controlled Chinese currency fell to a 22-month low of 6.93 to the dollar on Monday before recovering slightly on Tuesday.

Lu said the U.S. official’s comments were “groundless speculation and irresponsible.”