Russia says it will keep the roughly 100 servicemen it sent to Venezuela over the weekend, despite the US call for their removal.
Foreign Ministry spokeswoman Maria Zakharova said on Thursday that the forces would remain in the Latin American country "for as long as needed."
A Russian Air Force Antonov-124 cargo plane and a smaller Ilyushin Il-62 passenger jet brought the troops to Venezuela’s main airport outside the capital Caracas on Saturday.
"The presence of Russian specialists on Venezuelan territory is regulated by an agreement between the Russian and Venezuelan governments on military and technical cooperation that was signed in May 2001," Zakharova said, adding, "Neither Russia nor Venezuela are provinces of the United States."
In recent months, tensions have increased between Caracas and Washington with the US imposing sanctions on Venezuelan President Nicolas Maduro as well as his government.
In January, the US took the lead in recognizing Juan Guaido as Venezuela’s president after the head of the opposition-ruled Congress named himself the country’s interim chief executive. Washington has been pressuring other countries into following suit and has not ruled out using the military option to oust the government of Venezuelan President Nicolas Maduro.
US President Donald Trump also recently received Guaido's wife at the White House.
Russia, China, and Cuba, however, back Maduro’s government in the face of the US pressure.
Russian Foreign Minister Sergei Lavrov has accused Washington of trying to "organize a coup d'etat" in Venezuela.
Venezuela's military attache in Moscow was quoted by AFP as saying on Thursday that Russian troops were in the country under an agreement on military and technical cooperation and not to carry out a military operation.
"As for the presence of Russian specialists, we are talking about cooperation, military and technical cooperation," the attache, Jose Rafael Torrealba Perez said, adding, "We are absolutely not talking about Russia's military presence to carry out military operations."
On Tuesday, Zakharova confirmed and defended sending military experts to Venezuela, saying the dispatch is based on a military-technical cooperation agreement signed by the two countries in 2001.
Asked to comment on earlier reports about the arrival of two Russian planes in Venezuela, Zakharova said military experts had been dispatched to Venezuela under a bilateral agreement inked 18 years ago.
“The Russian Federation develops its cooperation with Venezuela in strict compliance with the constitution of this country and with full respect to its legislative norms. Russian [military] specialists' presence on the territory of Venezuela is regulated by the defense cooperation agreement that the Russian and the Venezuelan governments signed in May 2001,” she said.
Russian troops ‘no source of threat’
Elsewhere in her remarks, Zakharova also spurned allegations that the Russian military presence in Venezuela posed a threat to the region.
"Russia is not changing the balance of power in the region, Russia is not threatening anyone unlike citizens in Washington," she told reporters.
Referring to comments by Trump and US Secretary of State Mike Pompeo, who have respectively called for Russia to leave Venezuela, and vowed that Washington would try to end “Russian influence” in the Latin American country, Zakharova said, "Neither Russia nor Venezuela are provinces of the United States."
The Kremlin also said on Thursday that Washington should not "worry" about Moscow's relations with Venezuela, urging the United States to allow the crisis-stricken country to determine its own fate.
"We don't think that third countries should worry about our bilateral ties," President Vladimir Putin's spokesman Dmitry Peskov told reporters, adding, "We are not interfering in Venezuela's domestic affairs in any way and we expect third countries to follow our example and allow Venezuelans to decide their fate themselves."
Peskov added that Russian military specialists are in Venezuela to service pre-existing contracts for the supply of Russian arms.