MOSCOW - Russian President Vladimir Putin ratified an agreement on security guarantees with Belarus within the Union State, according to a document posted on the country's official legal information portal on Friday.

The agreement was originally signed by Putin and his Belarusian counterpart Alexander Lukashenko on Dec 6, 2024 in Minsk.

It was ratified by Russia's State Duma, or lower house of parliament, on Feb 18, and Russia's upper house of parliament, the Federation Council, on Feb 26.

Under the treaty, both parties pledge to undertake actions to support each other using all available means acceptable under international law to repel threats against any party or the Union State.

It regulates the procedure for the actions of the two countries in the presence of a real threat to the sovereignty of one or both of them.

The document also includes clauses on the deployment of Russian tactical nuclear weapons in Belarus.

According to the agreement, Russia's nuclear weapons can be used in response to the use of nuclear weapons or other weapons of mass destruction against either party, or in the event of aggression against any party with the use of conventional weapons, if it poses a critical threat to sovereignty and territorial integrity.