Oil prices reversed earlier gains to end lower on Thursday as investors continued to eye the latest developments regarding the Russia-Ukraine conflict.

The West Texas Intermediate (WTI) for April delivery lost 2.93 U.S. dollars, or 2.6 percent, to settle at 107.67 dollars a barrel on the New York Mercantile Exchange. Earlier in the session, the U.S. crude benchmark traded as high as 116.57 dollars per barrel, the highest level since September 2008.

Brent crude for May delivery decreased 2.47 dollars, or 2.2 percent, to close at 110.46 dollars a barrel on the London ICE Futures Exchange, after jumping to 119.77 dollars.

Investors monitored the ongoing Russia-Ukraine conflict and weighed the impact of the far-reaching Western sanctions against Russia.

Russia and Ukraine agreed to organize humanitarian corridors to evacuate civilians in the second round of talks in Belarus on Thursday, Advisor to the Head of the President's Office of Ukraine Mykhailo Podoliak confirmed on Twitter.

During the talks on Thursday, the two sides discussed military issues, humanitarian issues, and a future political settlement of the conflict, said Russian presidential aide Vladimir Medinsky, also the head of the Russian delegation.

Oil prices have spiked in recent days as the Russia-Ukraine tensions prompted fears about energy supply disruptions from key exporter Russia.

The Organization of the Petroleum Exporting Countries (OPEC) and its allies, a group known as OPEC+, announced on Wednesday that it would stick to existing plans for a modest oil output increase of 400,000 barrels per day in April.

The oil alliance noted in a statement after the 26th OPEC and non-OPEC Ministerial Meeting that the current volatility in the oil market is caused by geopolitical developments rather than changes in market fundamentals.

The International Energy Agency announced Tuesday that its member countries had agreed to release 60 million barrels of oil from their emergency reserves to ease any supply shortfall caused by the Russia-Ukraine conflict.