Two Russian air force planes landed at Venezuela’s main airport on Saturday carrying a Russian defense official and nearly 100 troops, according to media reports, amid strengthening ties between Caracas and Moscow.

A flight-tracking website showed that two planes left from a Russian military airport bound for Caracas on Friday, and another flight-tracking site showed that one plane left Caracas on Sunday.

That comes three months after the two nations held military exercises on Venezuelan soil that President Nicolas Maduro called a sign of strengthening relations, but which Washington criticized as Russian encroachment in the region.