Russian President Vladimir Putin said in an interview on Saturday that Moscow regards recent Black Sea exercises by the US and other NATO ships as “a serious challenge”.

"The United States and its allies in NATO are carrying out unplanned exercises in the Black Sea. Not only is a rather powerful naval group involved in these exercises, but also aviation, including strategic aviation. This is a serious challenge for us."

In an interview with Russian state broadcaster Vesti, Putin drew attention to the fact that B-51 ground attack aircraft are used, a relatively old model, stressing that the importance lies not in the carrier, but rather the strategic weapons that they carry.

The Russian President commented on the Russian Defense Ministry's suggestion that the country should hold a military exercise in the Black Sea in response to the actions of the US by saying, “it is unreasonable, and there is no need to accelerate tensions there.”

“The Russian Defense Ministry does not go further than escorting aircraft and ships," he added.

"Russia has nothing to do with the migrant crisis"

On the migrant crisis on the Belarus-Poland border, the Russian President insists that Moscow had absolutely nothing to do with the situation.

“I would like everyone to know, we [Russia] have nothing to do with this [migrant crisis]. They keep trying to lay some responsibility on us on any occasion and sometimes without occasion,” he said.

Putin described the situation of children who are stranded in freezing conditions along the frontier as “disastrous”.

Earlier, the Belarus State Border Committee reported that a large number of migrants, mostly Kurds, were making their way to Belarus' border with Poland.

These remarks come after Poland and other Western countries accused Moscow of coordinating with Minsk to send thousands of migrants to the border region.