US National Security Adviser John Bolton, commenting on the situation in Venezuela, said that the US would not tolerate what he described as "hostile meddling with the Western Hemisphere's shared goals of democracy, security, and the rule of law".
Bolton earlier called on Russia to "work with the international community to support the Venezuelan people", and accused Moscow of supporting legitimate Venezuelan President Nicolas Maduro, to whom he referred as a "corrupt dictator".
A diplomatic source from Caracas previously told Sputnik that a group of Russian military personnel had arrived in the Venezuelan capital to take part in consultations with the country's officials on defence industry cooperation.
The planes arrived in the Venezuelan capital on Saturday. Media earlier reported that an estimated 99 Russian military staff had arrived in Caracas on board two planes, which also delivered 35 tonnes of cargo. After the arrival of Russian Defence Ministry officials in Caracas, media reported that Venezuela had deployed S-300 air defence missile systems.
The source said that Russia and Venezuela had not recently signed contracts for the supply of the S-300 systems to Caracas, noting that the systems had been delivered to Venezuela in 2013.
READ MORE: Russian Military Officials Arrive in Venezuela for Defence Talks — Source
The source highlighted that the visit had nothing to do with the ongoing political crisis in the country, as it had been scheduled long before the trouble erupted.
US Secretary of State Mike Pompeo, while reacting to the Russian visit, said Monday that "the United States and regional countries will not stand idly by as Russia exacerbates tensions in Venezuela".
Venezuela has been in the midst of a severe political crisis for around two months, since the leader of the country's opposition, Juan Guaido, illegally proclaimed himself interim president, contesting the re-election of Maduro last year.
The self-proclaimed interim president immediately received support from the United States, which has also denounced Maduro's re-election, along with a number of other countries. Both Caracas and Moscow have expressed concerns that Washington may resort to military means to oust Maduro from power.
China, Cuba, Russia, and a number of other countries have endorsed Maduro as Venezuela's only legitimate president.