Senate Majority Leader Mitch McConnell said Democrats were too hasty in celebrating the shock spending deal they made with President Donald Trump last week, saying it is not as good as they believe.

“The deal is not quite as good as my counterpart thought it was,” the Senator from Kentucky told the New York Times' 'The New Washington' podcast, explaining that the battle for the debt limit increase will be delayed well beyond the initially agreed December deadline.

Last week, Trump overruled Republicans in Congress and struck a deal with senior congressional Democrats to raise the debt ceiling just as long as to ensure the government runs until December.

Republicans initially wanted an 18-month debt limit extension in a bid to avoid politically costly negotiations in the wake of the looming 2018 elections where most Senate and House seats will be up for grabs.

Trump later agreed to a 3-month extension suggested by Democrats but fiercely opposed by Republicans, telling reporters that after “a very good meeting with Nancy Pelosi and Chuck Schumer” they reached a deal that “will be very good.”

McConnell, however, told the Times that the debt limit will not have to be increased until well into 2018 as the newly passed legislation allows the Treasury to apply “extraordinary measures” to move money around and pay off the government’s skyrocketing debt.

“Since I was in charge of drafting the debt ceiling provision that we inserted into the flood bill we likely — almost certainly — are not going to have another debt ceiling discussion until well into 2018,” the senior Republican said.

He added this will take away the big wins from the Democratic Party who believed they gained an upper hand in the upcoming negotiations to keep the government running.

Republicans at the time slammed the President’s decision to overrule them and instead make a deal with the Democrats.

“The Pelosi-Schumer-Trump deal is bad,” Nebraska Senator Ben Sasse said on Twitter. “Hopefully we'll realize that negotiating with Democrats doesn't normally produce outstanding results,” seconded Mark Meadows, chairman of the House Freedom Caucus.

Paul Ryan, hours before the deal was reached, said a 3-month debt limit extension was “disgraceful” and “unworkable”.

Chuck Schumer celebrated the deal, saying “We think we made a very reasonable and strong argument. And, to his credit, (president) went with the better argument."

The Associated Press contributed to this report.