WASHINGTON - In an unexpected turnabout, Sen. Joe Manchin announced Wednesday that he had reached an expansive agreement with Senate Majority Leader Chuck Schumer which had eluded them for months on health care costs, energy and climate issues, taxing higher earners and large corporations and reducing federal debt.

Manchin, D-W.Va., whose resistance had long derailed sweeping legislation on those issues, abruptly revealed the agreement in a press release. It provided virtually no details on the accord.

Manchin, one of the most conservative Democrats in Congress, just last week said he would only agree this month to far more limited legislation curbing prescription drug costs and extending federal subsidies for health care costs.

He said he was open to considering a broader compromise on environment and tax issues after Congress returns from a summer recess in September, an offer that many Democrats thought dubious.

There was no immediate explanation why Manchin had suddenly agreed to the far broader package. In December, his resistance derailed a wide-ranging $3.5 trillion, 10-year social and environment bill that was President Joe Biden’s top domestic priority.

In his statement, Manchin said the measure “would dedicate hundreds of billions of dollars to deficit reduction by adopting a tax policy that protects small businesses and working-class Americans while ensuring that large corporations and the ultra-wealthy pay their fair share in taxes.”