A spokesman for Rosoboronexport, the export wing of Russia's arms corporation, told Russian news agencies that the helicopter training centre opened Friday "with Russian and Venezuelan specialists participating."

The centre that trains pilots to fly Russian-built Mil helicopters was built on the basis of a contract between Rosoboronexport and state-run Venezuelan Military Industrial Company Cavim, Interfax news agency quoted spokesman Vyacheslav Davydenko as saying.

The announcement came after two Russian military planes landed a week ago at the main airport outside Caracas and offloaded equipment and troops, ratcheting up international tensions.

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

US President Donald Trump called on Russia to "get out" of Venezuela, while Russia said 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.

The Kremlin and foreign ministry have insisted the troops came to Venezuela as part of a long-standing agreement on military and technical cooperation, while Venezuela's military attache to Moscow said there was no question of them taking part in a military operation.

Russia is aiming for "deepening of cooperation with the (Venezuelan) defence ministry," Rosoboronexport spokesman Davydenko said.

He said Venezuela, Russia's largest client in Latin America, has already received "a significant amount of Russian arms and military technology" including Sukhoi 30-MK2 fighter planes, Mil helicopters, tanks, armed personnel vehicles, artillery, air defence systems and Kalashnikovs.

"This has allowed the country in a very short time to obtain serious potential, reliably ensuring national security and defence capacity," he said.