US Secretary of State Mike Pompeo on Monday in a telephone conversation warned his Russian counterpart, Sergei Lavrov, that Washington will not stand idly by while Moscow "exacerbates" tensions in Venezuela.
"The secretary (Pompeo) told Russian Foreign Minister Lavrov that the United States and regional countries will not stand idly by as Russia exacerbates tensions in Venezuela," State Department spokesman Robert Palladino said in a statement.
During the call, Palladino said, the secretary of state told Lavrov that "The continued insertion of Russian military personnel to support the illegitimate regime of Nicolas Maduro in Venezuela risks prolonging the suffering of the Venezuelan people who overwhelmingly support interim President Juan Guaido."
According to the statement, the top US diplomat urged Russia to "cease its unconstructive behavior" and join other nations, including the overwhelming majority of nations in the Western Hemisphere, who - he said - are seeking a better future for the Venezuelan people.
On Sunday, two Russian military aircraft landed at Maiquetia International Airport, Venezuela's main air hub which also serves Caracas, according to reports by local media outlets and an opposition lawmaker.
According to the daily El Nacional, almost 100 Russian troops arrived in the South American country with 35 tons of unspecified equipment and other gear under the command of Maj. Gen. Vasily Tonkoshkurov.
The reason for the visit by Russian military personnel to Venezuela is not known, although Caracas and Moscow last December had said that they would begin "discussions on combined efforts" to raise the defense capabilities of the South American country to repel "possible attacks."
At that time, a squadron of Russian military planes, including two Tu-160 strategic bombers capable of carrying nuclear weapons, participated in joint military exercises with Venezuelan forces.
Russia is one of Maduro's biggest allies, backing him publicly against the challenge from Guaido, the president of the opposition-controlled Parliament, who on Jan. 23 proclaimed himself interim president and was shortly thereafter recognized by more than 50 nations, including the United States, as Venezuela's legitimate leader.