U.S. President Donald Trump took aim at insurers on Monday in an escalating threat to cut the health care subsidy payments that make Obamacare plans affordable, after repeatedly urging Republican senators to keep working to undo his Democratic predecessor’s healthcare law.

“If ObamaCare is hurting people, & it is, why shouldn’t it hurt the insurance companies & why should Congress not be paying what public pays?” Trump, a Republican, wrote on Twitter.

Trump, frustrated that he and Republicans have not been able to keep campaign promises to repeal and replace Obamacare, has threatened to let it implode. So far, the administration has continued to make the monthly subsidy payments, but withholding them would be one way to make good on Trump’s threat.

Republican Senator Rand Paul told reporters on Monday he spoke to Trump by phone and the president was considering taking executive action to address problems with the healthcare system.

Paul said he told Trump he thought he had the authority to create associations that would allow organizations – such as the AARP that represents retirees, or the U.S. Chamber of Commerce – to offer group health insurance plans.

The White House declined to comment on matter.

On Capitol Hill, Senate Finance Committee Chairman Orrin Hatch said senators were too divided to keep working on healthcare overhaul legislation, and that he and other senior Republicans would take that message to the White House.

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“There’s just too much animosity and we’re too divided on healthcare,” Hatch said in an interview. He said lawmakers could return to a healthcare overhaul later but for now should pivot to tax reform.

Some senators were not ready to drop healthcare, however.

Senator Bill Cassidy, Republican of Louisiana, met with Health and Human Services Secretary Tom Price and several Republican state governors at the White House on Monday to discuss a proposal Cassidy and others have made to send federal healthcare funds to the states in grants, Cassidy told reporters.

But Cassidy said he had not discussed bringing his proposal to the Senate floor with Senate leaders. And the third-ranking Republican senator, John Thune, told reporters Monday evening that until there is a proposal that can win a majority of senators’ support, “I think we’ve had our vote and we’re moving onto tax reform.”

Hatch, in the interview with Reuters, also said he thought Congress would have to approve new funds for the government’s cost-sharing reduction subsidies to insurers that Trump had been threatening to end. These subsidies lower the price of health coverage for the poor under the Affordable Care Act, known as Obamacare.

Insurers have asked the government to commit to making the $8 billion in payments for 2018, saying they may raise rates or leave the individual insurance marketplace if there is too much uncertainty.