MOSCOW - Russia is not considering the use of nuclear weapons in Ukraine and regards any transfer of them to Ukrainian authorities as entirely inadmissible, Russian Foreign Ministry Ambassador-at-Large Andrey Ivanovich Belousov said.

"We consider it necessary to refute the baseless speculation that Russia is supposedly considering the possibility of using nuclear weapons in Ukraine or threatening to use them," Belousov was quoted by TASS news agency as saying at the Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons on Wednesday.

Belousov said Moscow "is making efforts to prevent any armed confrontation between nuclear opponents" as it will bring escalation to a nuclear level.

"Russia is not interested in escalating tension. It is in our best interest that nuclear weapons are never used," the ambassador said.

Fire at Russian oil refinery extinguished

Separately, a large fire at an oil refinery in Russia's southern port of Tuapse, sparked by a Ukrainian drone attack, has been extinguished, the regional response center said on Thursday.

Local authorities first reported the blaze on Tuesday. The incident prompted the evacuation of nearby residents and led to the declaration of a regional state of emergency.

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The Kremlin said on Tuesday that Ukraine had targeted oil storage facilities with reserves designated for export, warning that the strike would worsen shortages in global oil markets.