MOSCOW  -  Venezuela’s deputy foreign minister Ivan Gil said on Thursday he does not rule out that more Russian military personnel may arrive in Venezuela under agreements already concluded with Russia, Interfax news agency reported.

The deputy minister also said Russian forces will stay in Venezuela as long as needed, and that there is no set period for their stay.

“The group of military specialists is (in Venezuela) in the context of our agreements and contracts for military-technical cooperation,” Interfax quoted Gil as saying.

Earlier the Kremlin said Russian military specialists are in Venezuela to service pre-existing contracts for the supply of Russian arms. The US special representative for Venezuela said last week U.S. Secretary of State Mike Pompeo has a list of options, including sanctions, that Washington could use to respond to the presence of Russian troops in Venezuela.

Meanwhile, Russia has opened a training center in Venezuela to help the country’s pilots fly Russian-made military helicopters, Russian state-owned industrial conglomerate Rostec said on Monday, Moscow’s latest gesture of support for President Nicolas Maduro.

Rostec said the centre was inaugurated on Thursday last week, the same day as the White House warned Moscow and other countries backing Maduro against sending troops and military equipment, saying the United States would view such actions as a “direct threat” to the region’s security.

Washington, which backs Venezuelan opposition leader Juan Guaido, issued the warning after two Russian air force planes carrying nearly 100 military personnel landed outside Caracas, a contingent the Kremlin described as military specialists.

Rostec said the new training facility, the location of which it did not disclose, had been set up with the help of Russian specialists and was designed to train Venezuelan pilots to fly Russian-made Mi-35M helicopter gunships as well as Russian-made military transport helicopters.

The facility was opened under a contract with Venezuelan state-owned weapons maker CAVIM. Rostec said it wanted to deepen military and technical cooperation with Venezuela’s ministry of defence if possible.

Russia, which has also supplied fighter jets, tanks, and air defence systems to Venezuela, has dismissed US criticism of its military cooperation with Caracas saying it is not interfering in the Latin American country’s internal affairs and poses no threat to regional stability. US President Donald Trump has said that “Russia has to get out” of Venezuela and that “all options” are open to force it to reduce its help for Maduro, raising the prospect of new U.S. sanctions against Moscow.