Republican negotiators have reportedly cautioned that a "significant gap" remains between the White House and GOP lawmakers on a deal to raise the borrowing limit with Rep. Garret Graves (R-La.) saying talks about important issues were akin to the process of buying a used car.

Tuesday's talks between both sides remained inconclusive and Wall Street has begun showing signs of cracks with major indices declining over 1%.

Significant Gap: GOP negotiators Graves and Rep. Patrick McHenry (R-N.C.) told reporters late Tuesday afternoon that the fundamental issue is about topline discretionary spending levels, according to a report by The Hill.

"There is a significant gap between where we are and where they are on finances," Graves said. "Unless and until the White House recognizes that this is a spending problem, then we're gonna continue to have a significant gap."

Following Tuesday's talks, no plans for further meetings with White House officials have been unveiled so far but Republicans said they plan to stay at the Capitol and noted the White House team is welcome back if they want to meet, the report said.

'Used Car': Although Graves indicated some areas witnessed substantial progress, he said talks about the most important issues were similar to the process of buying a used car.

"They're gonna say, 'Well I gotta go talk to my manager – oh sorry, the manger won't drop the price, but he'll throw in car mats.' Like, that doesn't do it," Graves said. "And I feel like we've been through a few of those iterations, which is inappropriate. We need to be able to have empowered negotiators in the room."

Republicans have flatly rejected suggestions from the White House to increase revenue via tax raises or expanding Medicare's ability to negotiate drug prices, the report said.

Although some House Republicans have doubted Treasury Secretary Janet Yellen's forecast the U.S. could default on its debt obligations as early as June 1, GOP negotiators said they are trying to meet that deadline. "The backstop that we're operating under is June 1 until I know better," Graves said according to the report.