Fitch Ratings said on Friday its top AAA debt rating for the United States would not be directly impacted by a possible federal shutdown, which will begin on Saturday if lawmakers fail to clinch a deal to fund the government.

“Partial federal government shutdowns have occurred in the past and this shutdown does not have a direct impact on the sovereign’s ‘AAA’/Stable rating,” the rating agency said in a statement.

On Friday, the U.S. Senate was racing to avert a government shutdown that will begin at midnight if it cannot reach an agreement on legislation that will fund the government through Feb. 16.

The House of Representatives approved the measure late Thursday, which would be the third such temporary deal since the new fiscal year began in October.

“Its main implication for the U.S.’s sovereign creditworthiness would depend on whether it foreshadowed a further destabilization of US budget policymaking, or brinkmanship over the federal debt limit,” Fitch said.

The Congressional Budget Office has said the government would run out of cash in late March and early April when the Treasury Department exhausts extraordinary measures to fund various federal obligations.