Investment guru Jim Cramer warns that the seemingly endless surging stock market may tumble if Washington lawmakers don’t reach a deal on another coronavirus relief package.

“If we don’t have a deal, we’ve got to have a sell-off,” Cramer said on CNBC.

“It’s not like we can just avoid a deal and say it doesn’t matter. And that’s what I’m getting concerned about,” he said.

Shares on Wall Street shrugged off a sluggish start and closed higher on Thursday, with the Nasdaq ending the session above 11,000 for the first time as investors hoped for a new fiscal stimulus package, Reuters reported.

The benchmark S&P 500 and blue-chip Dow were about 1% and 7% away from their own peaks scaled in February.

"Markets have been incredibly resilient, there is a big fear of missing out and it is the old stalwarts, the technology leaders that keep driving the market higher," said Sal Bruno, chief investment officer at IndexIQ in New York.

Senate Majority Leader Mitch McConnell said on Thursday the U.S. economy needs an "additional boost" to cope with fallout from the coronavirus pandemic, as Republicans and Democrats remained far apart about what to include in another wave of relief, Reuters explained.

Republican President Donald Trump, who has threatened to act unilaterally if Congress does not agree on a further aid package, said he was working on an executive order targeting eviction protections and unemployment benefits.

Democrats have been pushing for a $3.4 trillion relief bill, while Republicans last week proposed $1 trillion.

Trump's executive order would also address student loan repayment options and payroll tax cuts - a proposal Trump has raised repeatedly, which was met with little enthusiasm from Democrats or his fellow Republicans.

Congress' top two Democrats and White House negotiators have been talking for nearly two weeks on next steps to address a crisis that has killed more than 157,000 Americans and thrown tens of millions out of work.