Belarus said on Tuesday that there was a significant grouping of Ukrainian troops massed near its border and warned that this posed a threat to its security.

Belarus said a significant number of Ukrainian soldiers are positioned at its borders warning that the probability of an armed escalation has been high for a long time.

"At present, a significant grouping of the Ukrainian army is concentrated in the immediate vicinity of the Belarusian-Ukrainian section of the state border," the Defense Ministry said on Tuesday on its Telegram account.

"The probability of armed provocations, which can escalate into border incidents, has been high for a long time," it added, stressing that it would take "measures to adequately respond" but would act in a restrained manner.

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Belarusian President Alexander Lukashenko stated earlier that his country will only act in self-defense if attacked by Ukraine.

Lukashenko said on Tuesday that over 150 joint events with Russia were planned this year, including a major drill called "Union Shield 2023" in September.

No imminent threat from Belarus

On his part, Mykhailo Podolyak, a senior advisor to Ukraine's President, told Reuters on Tuesday that Belarus was increasing its "aggressive and militaristic rhetoric" ahead of the first anniversary of the Russian-Ukrainian war, adding however that Kiev sees no indications that Belarus is preparing to carry out any threats.

Podolyak's comment came in response to Belarus' warning of a significant grouping of Ukrainian servicemembers on its borders.

"We do not see any logistics action in Belarus aimed at forming a strike force. Nor do we see the accumulation of equipment needed for a ground offensive," the official said to Reuters.

"Official Minsk is unwaveringly supporting Russia on the information side. Nevertheless, we have the northern direction (facing Belarus) under special control."

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Union State alliance

On October 10, Lukashenko said Minsk and Moscow agreed on deploying a joint military group as the security situation was declining on the western border of the Union State, a supranational union between Belarus and Russia founded in 2000 with the objective of integrating both nations' political, economic, and defense policies.

In early December, Russian President Vladimir Putin said at a meeting with Belarusian President Alexander Lukashenko that Moscow and Minsk are not only good neighbors but also have developed ally relations, including economic cooperation.

On New Year's Eve of 2023, Russia announced that Moscow and Mink's bilateral relations have reached new highs in light of recent geopolitical events that have increased both countries' commitment to the Union State.

The Union State's military doctrine declares that any aggression against either member is aggression against both, which would call for "appropriate measures" to be taken "using all the forces and means" at the countries' disposal to neutralize the threat.