President Donald Trump appeared to lend support on Friday to protestors in several US states who have been demonstrating against stay-at-home orders imposed because of the coronavirus pandemic.

"LIBERATE MINNESOTA!" Trump tweeted. "LIBERATE MICHIGAN!"

The Republican president followed those tweets with another saying: "LIBERATE VIRGINIA, and save your great 2nd Amendment. It is under siege!"

All three states -- Minnesota, Michigan and Virginia -- have seen demonstrations this week against the lockdowns imposed by their governors in a bid to prevent the spread of the highly contagious virus. All three states also have Democratic governors and Trump's tweets appeared to be politically motivated.

Trump also lashed out on Friday at New York Governor Andrew Cuomo, another Democrat, saying he should "get out there and get the job done." New York state with more than 10,000 deaths is the epicentre of the virus outbreak in the United States.

Cuomo, who has said previously he does not want to get in a "fight" with the president, shot back: "If he's sitting home watching TV, maybe he should get up and go to work."

More than 40 of the 50 US states have imposed stay-at-home orders and about 95 percent of the US population is currently under some form of lockdown in accordance with social distancing guidelines from the federal government.

Trump unveiled plans on Thursday for states to reopen their economies but largely left the decision to the governor of each state. Michigan Governor Gretchen Whitmer told reporters on Friday that she hoped Trump's tweets were "not encouraging more protests."

"There is a lot of anxiety and I think, you know the most important thing that anyone with a platform can do is try to use that platform to tell people, 'We are going to get through this,'" Whitmer said. "We will reengage our economy when it's safe," she said.

Virginia Governor Ralph Northam shrugged off Trump's tweets. "As the governor of the commonwealth of Virginia I, along with my staff, are fighting a biological war," Northam said. "I do not have time to involve myself in Twitter wars."

Asked about Trump's tweets, Minnesota Governor Tim Walz said his "first responsibility is the protection of Minnesota's people. "I just don't have time to try to figure out why something like that would happen," he said. "We're leading as we were asked. If I thought we could go back to work tomorrow that's exactly what we would do."

'Unhinged rantings'

While Whitmer, Northam and Walz reacted cautiously to Trump's tweets, Washington Governor Jay Inslee, a former candidate for the Democratic presidential nomination, was furious. "The president's statements this morning encourage illegal and dangerous acts," Inslee said. "He is putting millions of people in danger of contracting COVID-19. His unhinged rantings and calls for people to 'liberate' states could also lead to violence," Inslee warned in a statement. "The president is fomenting domestic rebellion and spreading lies, even while his own administration says the virus is real and is deadly, and that we have a long way to go before restrictions can be lifted."

The Second Amendment reference in Trump's tweet refers to the part of the US Constitution giving Americans the "right to bear arms." Northam, the Virginia governor, last week signed legislation enacting several gun control measures in the state.

The largest protest against stay-at-home orders was on Wednesday in Lansing, the state capital of Michigan, which with more than 2,200 deaths has the third-highest toll in the country. There have been more than 230 COVID-19-related deaths in Virginia and more than 110 in Minnesota. The Michigan protest in defiance of the stay-at-home orders imposed by Governor Whitmer attracted around 3,000 demonstrators, some of whom were armed.

It was organized by a coalition of right-wing groups calling themselves "Michiganders Against Excessive Quarantine."

"We Want to Work" and "End the Lockdown" read signs carried by the protestors, a number of whom wore red pro-Trump "Make America Great Again" hats and waved "Trump 2020" flags. About 800 protestors demonstrated outside Minnesota Governor Walz's residence in St. Paul on Friday, according to the Star Tribune newspaper, under the banner of "Liberate Minnesota."