DUBAI--Saudi Arabia and Russia, the world's biggest oil exporters, deepened oil cuts on Monday, sending prices higher despite concerns over a global economic slowdown and possible further interest rate increases from the U.S. Federal Reserve. OPEC+, which groups the Organization of the Petroleum Exporting Countries (OPEC) and allies led by Russia, has already been cutting supply to boost prices since November last year due to weaker Chinese demand and rising U.S. supply but so far has failed to move them much from a range of $70-$80 a barrel. Saudi Arabia said it would extend its voluntary oil output cut of one million barrels per day (bpd) for another month to include August, adding that the cut could be extended beyond that month. Shortly after the Saudi announcement, Russian Deputy Prime Minister Alexander Novak said Moscow would cut its oil exports by 500,000 barrels per day in August. The cuts amount to 1.5% of global supply and bring the total pledged by OPEC+ to 5.16 million bpd. Later on Monday, Algeria said it would cut oil output by an extra 20,000 barrels from Aug. 1-31 to support efforts by Saudi Arabia and Russia to balance and stabilise oil markets, its energy ministry said. The voluntary cut will be on top of a 48,000 barrel reduction decided in April, it said. Libyan Oil Minister Mohamed Oun said his country welcomed the Saudi decision which will have "positive impact on market balance between global producers, consumers, and on global economy." OPEC+, which pumps around 40% of the world's crude oil, already has in place cuts of 3.66 million bpd, amounting to 3.6% of global demand, including 2 million bpd agreed last year and voluntary cuts of 1.66 million bpd agreed in April and extended to December 2024.