Oil jumped to the highest since July 2015 after Saudi Arabia signaled it's ready to cut output more than earlier agreed and non-OPEC countries including Russia pledged to pump less next year.

Futures rose as much as 5.8% in New York and 6.6% in London. Saudi Energy Minister Khalid Al-Falih said Saturday the biggest crude exporter will “cut substantially to be below” the target agreed last month with members of OPEC. His comments followed a deal by 11 non-OPEC countries including Mexico to join forces with the group and trim output by 558,000 barrels a day next year, the first pact between the rivals in 15 years.

U.S. oil futures have gained about 20% since the Organization of Petroleum Exporting Countries agreed on Nov. 30 to cut output for the first time in eight years. Saudi Arabia, which initiated OPEC's decision in 2014 to pump without limits, is leading efforts to take back control of the market. The OPEC and non-OPEC plan encompasses countries that supply 60% of the world's crude, but excludes major producers such as the U.S., China, Canada and Brazil.