The White House on Monday called GOP efforts to defund Obamacare and win more spending cuts at the risk of a government shutdown or default “utterly irresponsible” and warned the president would not negotiate with Republicans.

“Congress needs to act responsibly to ensure that the government does not shut down,” White House spokesman Jay Carney told reporters. “[President Obama] has made it abundantly clear that fiddling around with the prospect of default is utterly irresponsible and we cannot do it.”

The president phoned Speaker John Boehner, R-Ohio, late Friday afternoon to tell him he will not negotiate with Republicans on raising the debt ceiling or defunding his signature health care reform bill. Boehner told Obama he was “disappointed” to hear the president's response.

“Given the long history of using debt limit increase to achieve bipartisan deficit reduction and economic reforms, the Speaker was disappointed but told the president that the two chambers of Congress will chart the path ahead,” a Boehner aide said. “It was a brief call.”

If Congress and the White House cannot agree to a spending bill by the end of the month, the government will shutdown on Oct. 1. By mid-October, the U.S. Treasury will also hit its borrowing limit, the amount needed to cover bills Congress has already racked up for government spending.

Obama and his top aides for months have said they will not give in to Republican insistence to use a continuing resolution or debt ceiling increase to fight for spending cuts or defunding Obamacare.

Boehner and other Republicans argue that the debt ceiling is an opportunity to pursue spending cuts, and last week called for Obama to negotiate a deficit-cutting package with Senate Democrats.

House Republicans on Friday passed a stopgap spending bill that defunded the president’s signature health care reform bill.

With Democrats controlling the Senate, Carney said that the House GOP bill had “no chance” of becoming law.

He said there have been 40 times since former President Ronald Reagan took office when Congress has raised the debt ceiling without attaching other provisions, adding that neither side has ever threatened to throw the government into default.

The White House has reached out to congressional leaders in hopes of meetings later this week.