February futures for Brent crude were stable at $76.03 per barrel, while January futures for American West Texas Intermediate crude rose by 3 cents to $71.35 per barrel.

Both contracts had seen a slight increase on Monday: Brent went up by 19 cents to $76.03 per barrel, and WTI by 9 cents to $71.32.

OPEC+ promised to cut production by 2.2 million barrels per day in the first quarter of 2024, but investors remain doubtful that this will decrease overall supply due to expected production increases in non-OPEC countries.

ANZ Research analysts noted the continued rise in U.S. shale oil production and unexpectedly high output from other non-OPEC producers.

Brent crude prices fell from over $80 per barrel in early December, and WTI from over $77 per barrel.

Both Brent and WTI are in a contango market structure, indicating that futures contracts for the first few months of 2024 are priced lower than later contracts. This suggests investor expectations of lower demand or sufficient supply of crude oil during these periods.

"The oil market is closely monitoring the new reports from OPEC and the International Energy Agency, as well as the negotiations at COP28," the statement read.

At the COP28 summit, measures to reduce greenhouse gas emissions were discussed, but a phased-out fossil fuel reduction, demanded by many countries, was not mentioned, drawing criticism from the USA, EU, and climate-vulnerable countries.

More than 100 countries aimed for an agreement that would signify the end of the oil era, but faced resistance from OPEC members.

In addition to the COP28 negotiations, the market is also paying attention to this week's key central banks' interest rate policies and U.S. inflation data.

The U.S. Consumer Price Index (CPI) report is due on Tuesday, with the Federal Open Market Committee's (FOMC) two-day meeting on monetary policy concluding on Wednesday.

Decisions on interest rates are also expected from the European Central Bank (ECB) on Wednesday and the Bank of England (BoE) on Thursday.

January's demand for Saudi crude oil from Chinese refineries, the world's largest oil importer, hit a five-month low, as unexpectedly high prices led buyers to seek cheaper supplies elsewhere.

Saudi Arabia competes with Russia as the largest oil supplier to China.