The U.S. is in danger of losing its triple-A sovereign credit rating later this year, Fitch said on Wednesday, warning an ongoing government shutdown could soon start to impact its ability to pass a budget.
A stalemate between President Donald Trump and congressional Democrats over a spending package to fund nine government agencies entered its 19th day on Wednesday. It comes at a time when lawmakers are deeply divided over the president's demand for money for a border wall.
"I think people are looking at the CBO (Congressional Budget Office) numbers. If people take the time to look at that you can see debt levels moving higher, you can see the interest burden in the U.S. government moving decidedly higher over the next decade," James McCormack, Fitch's global head of sovereign ratings told CNBC's "Squawk Box Europe" on Wednesday.
"There needs to be some kind of fiscal adjustment to offset that or the deficit itself moves higher and you're essentially borrowing money to pay interest on the debt. So there is a meaningful fiscal deterioration there, going on the United States," he added.
Speaking later at an event in London, McCormack continued: "If this shutdown continues to March 1 and the debt ceiling becomes a problem several months later, we may need to start thinking about the policy framework, the inability to pass a budget ... And whether all of that is consistent with triple-A."
"From a rating point of view it is the debt ceiling that is problematic," he added, according to Reuters.
In a prime-time television address late Tuesday, Trump made his case for a wall and strengthened security at the U.S.-Mexico border in graphic fashion, highlighting multiple grisly examples of Americans allegedly murdered by illegal immigrants.
Democratic congressional leaders Nancy Pelosi, the House speaker, and Chuck Schumer, the Senate minority leader, immediately responded to Trump's harrowing remarks, denouncing his dark language and again calling for the government to reopen.
The dueling addresses amounted to little more than high-stakes theater, with each side repeating their firm stances on the shutdown.
In a commentary published Friday, Fitch said its sovereign credit view of the world's-largest economy hinged on whether the ongoing shutdown was likely to morph into a "more pronounced destabilization of fiscal policymaking."
That includes "brinkmanship" over the country's debt limit, Fitch said, referring to the current political impasse in Washington.
The rating agency also points out the U.S. debt limit is due to come back into force from March.
"We view the risk of a failure to lift the debt limit in time to prevent a U.S. federal debt default as remote," Fitch said in its commentary, before adding: "Evidence of greater dysfunction in fiscal policymaking could still contribute to negative pressure on the U.S. rating — (and) this is especially the case as deficits continue to increase."
In June 2018, sovereign analysts at S&P Global reaffirmed their 'AA+' credit rating for the U.S., adding the country's outlook was "stable."
Responding to a request for comment on Wednesday, S&P said the government shutdown had not changed its view.
While Moody's did not respond when contacted by CNBC on Wednesday, the rating agency reportedly said late December that a partial government shutdown would not have a material impact on the country's credit profile.
— CNBC's Kevin Breuninger contributed to this report.