MOSCOW

Russia believes it has a responsibility to assist Cuba in providing critical energy resources for the country's life support systems, as Moscow cannot simply stand by and watch its ally suffer due to fuel scarcity, the Kremlin said on Monday.

"Under conditions of a severe blockade, our Cuban friends need petroleum products and oil. This is necessary for the operation of the country's life-support systems, for generating electricity, and for providing medical and other services to the population," Kremlin spokesman Dmitry Peskov said at a press briefing in Moscow.

Asked why the US Coast Guard allowed the passage of the Russian tanker, the official said Moscow had discussed the possibility of humanitarian oil supplies to Cuba with Washington in advance.

"We are glad that this shipment of petroleum products has arrived on the island," he added.

Commenting on Finnish President Alexander Stubb's statement that Russia may announce a general mobilization, Peskov said no new waves of military mobilization are planned in Russia, adding, "Such a topic is not on the agenda."

Responding to a question about the possibility of selling energy resources to the EU, Peskov said Russia is ready to be a reliable supplier of energy resources to European markets as well.

The official confirmed that the Russian-Serbian gas contract, which expires on March 31, will continue.

Earlier on Monday, Serbian President Aleksandar Vucic announced that the contract had been extended for three months.

"Russia has been and remains ready to continue being a reliable supplier of energy resources to any world markets, including the European one. We are particularly committed to our obligations regarding such friendly and brotherly countries as Serbia," Peskov said.