"We recommend that the United States stop threatening Venezuela, smothering its economy and pushing it towards civil war in open violation of international law," foreign ministry spokeswoman Maria Zakharova said in a statement.

On Friday, a statement from the US National Security Advisor John Bolton warned "actors external to the Western Hemisphere against deploying military assets to Venezuela".

But Zakharova, in her statement Saturday, said Russia had made it clear it was not sending a military contingent to Venezuela.

Two Russian military planes landed a week ago at the main airport outside Caracas and offloaded equipment and troops, ratcheting up international tensions.

Russian officials insist the troops came to Venezuela as part of a long-standing agreement on military and technical cooperation.

But US President Donald Trump has called on Russia to "get out" of Venezuela, with Russia saying its troops will stay for as long as needed.

The military specialists are apparently helping to fix a malfunctioning Russian S-300 ground-to-air missile system, US envoy Elliott Abrams said Friday.

Russia and Venezuela signed a military cooperation treaty in 2011 involving the sale of Russian weapons to Venezuela.

Earlier Saturday, Rosoboronexport, Russia's state arms export company said it has opened a training centre for military helicopter pilots in Venezuela, after Moscow flew in troops and equipment.

Venezuela, Russia's largest client in Latin America, has already received "a significant amount of Russian arms and military technology", Rosoboronexport spokesman Davydenko added.

The United States and more than 50 other countries recognise Venezuelan opposition leader Juan Guaido as interim president. Russia, along with China, backs President Nicolas Maduro.