"The American side has made a move which, it is important to note, hasn't been provoked by anything, to worsen Russian-US relations. [It includes] unlawful restrictions, attempts to influence other states of the world, including our allies, who are interested in developing and keeping relations with Russia," said Putin during an interview with the Rossiya 1 TV channel on Sunday.

Earlier in the week, after the US Congress approved new sanctions against Russia, Iran and North Korea, the Russian foreign ministry announced that Moscow had informed Washington that its diplomatic staff in Russia must be reduced to 455.

“We've been waiting for quite a long time that maybe something would change for the better, we had hopes that the situation would change. But it looks like, it's not going to change in the near future... I decided that it is time for us to show that we will not leave anything unanswered," he added.

"From the perspective of a working diplomatic mission, [the measure] is fairly sensitive," Putin said.

Putin added that there are “important spheres of cooperation" between the US and Russia which he hoped would not be hurt by America's anti-Russia policies.

He stressed that both countries had recently obtained "concrete" results in de-escalating the situation in Syria, which has been has been fighting different foreign-sponsored militant and terrorist groups since March 2011. UN Special Envoy for Syria Staffan de Mistura estimated last August that more than 400,000 people had been killed in the crisis until then.

"We also work together on fighting illegal migration and organized crime in a broad sense. There are also issues of cybersecurity," the Russia president added.