Oil prices were little changed on Tuesday against a backdrop of uncertainty over voluntary output cuts by the OPEC+ group of producers, tensions in the Middle East and some encouraging economic signals in Europe.

Brent crude futures edged down by 25 cents, or 0.3%, to $77.78 a barrel by 1301 GMT. U.S. West Texas Intermediate crude futures lost 21 cents, or 0.3%, to $72.83.

Comments by Saudi Arabia's energy minister that OPEC+ production cuts could continue past the first quarter of 2024 lent some price support, said OANDA analyst Kelvin Wong.

Oil prices had declined on Monday on doubts that OPEC+ supply cuts would have a significant impact, said CMC Markets analyst Tina Teng.

On Tuesday, however, the Kremlin said that the cuts agreed by the OPEC+ group will take time to kick in.

The Organization of the Petroleum Exporting Countries and allies including Russia, together known as OPEC+, agreed on Thursday to voluntary output cuts of about 2.2 million barrels per day (bpd) for the first quarter of 2024.

At least 1.3 million bpd of those cuts, however, were an extension of voluntary curbs that Saudi Arabia and Russia already had in place.

The additional cuts were below the 1 million bpd reduction that was already baked into market expectations in the run-up to the OPEC+ meeting, FGE analysts wrote in a note, adding that in practice they expect the overall OPEC+ cut to be closer to 500,000 bpd more than the reductions to fourth-quarter output.

Meanwhile, the resumption of fighting in the Israel-Hamas war has stoked supply concerns, as did attacks on three commercial vessels in international waters in the southern Red Sea.

There was a bright spot on the demand side, with European Central Bank board member Isabel Schnabel telling Reuters the bank can take further interest rate hikes off the table after a "remarkable" fall in inflation.

In the United States, however, data on Tuesday showed factory orders fell by more than analysts had expected in October and the most in more than three years, raising concerns about the health of U.S. demand.

That bolstered the view that increases to interest rates are beginning to limit spending, analysts said.