Saudi Arabia's Minister of Energy Prince Abdulaziz bin Salman Al-Saud speaks via video link during a virtual emergency meeting of OPEC and non-OPEC countries, following the outbreak of the coronavirus disease (COVID-19), in Riyadh, Saudi Arabia April 9, 2020.

Oil prices fell on Monday as oversupply concerns continue to pressure prices, even as OPEC and its allies agreeing to cut production by 9.7 million barrels per day. The deal, which was finalized on Sunday after marathon discussions that spanned four days, is the single largest output cut in history.

U.S. West Texas Intermediate crude fell 1.54% to settle at $22.41 per barrel, while international benchmark Brent crude rose 33 cents to $31.81 per barrel. Earlier in the session WTI had been up as much as 8%.

The group, known as OPEC+, initially proposed cutting production by 10 million bpd — amounting to some 10% of global oil supply — on Thursday, but Mexico opposed the amount it was being asked to cut, holding up the final deal. Under the new agreement, Mexico will cut 100,000 bpd, instead of its initial allocation of 400,000 bpd.

The 9.7 million bpd cut will begin on May 1, and will extend through the end of June. The cuts will then taper to 7.7 million bpd from July through the end of 2020, and 5.8 million bpd from Jan. 2021 through April 2022. The 23-nation group will meet again on June 10 to determine if further action is needed.

"Unprecedented measures for unprecedented times," Ed Morse, Citi's global head of commodities, wrote in a note to clients on Sunday. Morse said the cut will have a significant impact in the second half of the year and help lift prices to the mid-$40s by year-end, but that there will be short-term pain while the market rebalances.

"It's simply too late to prevent a super-large inventory build of over one billion barrels between mid-March and late May and to stop spot prices from falling into single digits," he said.