(Reuters) – The oil futures gained early Tuesday as investors considered the possibility of additional sanctions against Russia’s energy sector. OPEC also warned that it was impossible to raise output enough to compensate for the loss in supply.

Futures increased 0.9% to $99.33 a barrel. U.S. West Texas Intermediate contract prices were up 1.1% at $95.33 a barrel by 0019 GMT.

Due to concerns about coronavirus lockdowns occurring in China, both contracts were settled around 4% Monday. This was ahead of a large oil reserve release planned by the International Energy Agency members.

On Monday, foreign ministers stated that some European Union members are preparing proposals to impose an EU oil embargo upon Russia after its invasion of Ukraine. However, members are not yet in agreement on how to treat crude oil from Russia. Russia calls the actions of its troops in Ukraine “special operations”.

Edward Moya is a senior analyst at OANDA. He stated, “The oil markets are still vulnerable to a big shock if Russian Energy is sanctioned and that risk is on the table.”

He said that oil prices would play a tug-of war here because crude inventories are still low. However, energy traders won’t be able to shake off these constant announcements about new COVID limitations in China.

The rise in oil prices on Tuesday came after an OPEC warning that 7 million barrels per hour of Russian oil and liquids exports were at risk from sanctions and voluntary actions. It was also clear that these volumes would not be replaced.

The IEA member countries plan to release around 240,000,000 barrels within the next six-months to help calm volatile oil market markets. 180 million barrels will be taken from U.S. stockspiles and released at a rate 1 million bpd beginning in May.