WASHINGTON — Two leading senators said Tuesday they have the “basic outlines” of a bipartisan agreement to resume federal payments to health insurers that President Trump has blocked.

Both said in separate interviews that they still have unresolved issues but expressed optimism that a compromise was near.

The agreement would involve a two-year extension of federal payments to insurers that Trump halted last week, said Sen. Lamar Alexander (R-Tenn.).

Unless the money is quickly restored, insurers and others say that will result in higher premiums for people buying individual policies and in some carriers leaving unprofitable markets.

In exchange, Republicans want Congress to give states “meaningful” flexibility to ease some coverage requirements under President Barack Obama’s health care law.

“The definition of meaningful,” Alexander said when asked what the remaining stumbling blocks were.

Alexander agreed with his negotiating partner, Sen. Patty Murray ( D-Wash.), who said the two lawmakers “have the basic outlines” of an agreement but have differences to bridge.

Trump’s halt of the payments and worries about its impact have galvanized lawmakers in both parties to take action to prevent it. Even so, strong opposition by some conservatives means the fate of a compromise would be uncertain.

Trump has said he wants the two parties to reach an agreement as an interim step toward his goal of dismantling Obama’s law — an effort that crashed this summer in the GOP-run Senate. Alexander said he’s spoken to Trump twice about the subject in the past few days “and he’s encouraged me to get a result with Sen. Murray.”

The two lawmakers planned to brief colleagues in separate GOP and Democratic Senate lunches. Alexander chairs the Senate health committee and Murray is that panel’s top Democrat.

Under Obama’s 2010 law, the government must pay insurers for reducing out-of-pocket expenses for lower-earning customers.

A federal judge has ruled that Congress hadn’t legally approved the payments, but Obama — and initially Trump — continued them anyway. After months of threatening to halt them, Trump did just that last week.

Trump and some Republicans consider them bailouts to carriers. But Democrats and some Republicans say halting them will create chaos in insurance market places.

The so-called cost-sharing reductions cost around $7 billion this year and lowered expenses like co-payments and deductibles for more than 6 million people.