Donald Trump claims he has "total authority" to decide how and when to reopen the American economy after weeks of tough lockdown measures aimed at fighting coronavirus.
But Republican and Democrat governors have claimed they have the primary constitutional responsibility for ensuring public safety in their states and would decide when it is safe to begin a return to normal life.
Democratic leaders in the northeast and along the west coast announced separate state plans to co-ordinate their efforts to scale back stay-at-home orders or reopen businesses on their own timetables, even as Trump tried to say it was his call.
"When somebody is president of the United States, the authority is total," Trump said at Monday's confrontational White House coronavirus briefing. "The governors know that."
Anxious to put the twin public health and economic crises behind him, Trump has backed federal social distancing recommendations that expire at the end of the month. But governors and local leaders have instituted mandatory restrictions, including shutting schools and closing non-essential businesses.
On Twitter, Trump wrote that some are "saying that it is the Governors decision to open up the states, not that of the President of the United States & the Federal Government. Let it be fully understood that this is incorrect ... it is the decision of the President, and for many good reasons."
Trump can pressure states to act or threaten them with consequences, but the Constitution gives public health and safety responsibilities primarily to state and local officials.
Meanwhile, the President's guidelines have little force. Governors and local leaders have issued orders that carry fines or other penalties and, in some jurisdictions, extend into the early summer.
"All of these executive orders are state executive orders and so it would be up to the state and the governor to undo a lot of that," Chris Sununu, the Republican Governor of New Hampshire, told CNN.
Tom Wolf, Pennsylvania's Democratic governor, told reporters that until people are healthy, reopening the economy is "not going to work".
"Seeing how we had the responsibility for closing the state down, I think we probably have the primary responsibility for opening it up."
Wolf joined governors in New York, New Jersey, Connecticut, Delaware and Rhode Island in agreeing to co-ordinate their actions.
The governors of California, Oregon and Washington announced a similar pact. Each state is building its own plan, but the west coast states have agreed to work together, put their residents' health first and let science guide their decisions.
New Jersey Governor Phil Murphy stressed the efforts would take time.
"The house is still on fire," he told reporters. "We still have to put the fire out, but we do have to begin putting in the pieces of the puzzle that we know we're going to need to make sure this doesn't reignite."
Though Trump abandoned his goal of rolling back social distancing guidelines by Sunday, he has been itching to re-open an economy that has dramatically contracted as businesses have shuttered, leaving millions of people out of work and struggling to obtain basic commodities. The closure has also undermined Trump's re-election message, which hinges on a booming economy.
Trump's claim that he could force governors to reopen their states represents a dramatic shift in tone. For weeks, the President has argued that states, not the federal government, should lead the response to the crisis. And he has refused to publicly pressure states to enact stay-at-home restrictions, citing his belief in local control of government.
"The government doesn't get opened up via Twitter. It gets opened up at the state level," Michigan Democrat governor Gretchen Whitmer said.
Mississippi Republican governor Tate Reeves, a supporter of Trump, said the question of when to lift restrictions would be "a joint effort" between Washington and the states.
Talk about how and when to reboot the nation's economy has come as Trump has bristled at criticism that he was slow to respond to the virus and that lives could have been saved had social distancing recommendations been put in place sooner.
That frustration was amplified by comments by Dr Anthony Fauci, the nation's top infectious diseases expert. Asked on Sunday on CNN if acting earlier could have saved lives, Fauci said: "Obviously, you could logically say that if you had a process that was ongoing and you started mitigation earlier, you could have saved lives."
Trump responded by reposting a tweet that referenced Fauci's comments and included the line, "Time to £FireFauci," raising alarms that the President might consider trying to oust the doctor.
Trump has complained to aides about Fauci's positive media attention and his willingness to contradict the President in interviews and from the briefing room stage, two Republicans close to the White House told AP on condition of anonymity.
But at Monday's briefing, Trump said, "I'm not firing him. I think he's a wonderful guy."