The Embassy of Russia in the USA has strongly condemned the removal of Russian flags from its previously seized diplomatic property in San Francisco, demanding that the state symbols be returned.
After that, the Americans demanded closing the Russian consulate in San Francisco and two buildings of trade missions in Washington and NY before September 2.
Russian Federation considers such a move as an "extremely unfriendly step", and demands an immediate return of the flags, the embassy added. On Wednesday this week they removed Russian flags from the roofs of the San Francisco consular office and the office of the Russian Trade Representative in Washington, DC. Flags have been stolen from the buildings in San Francisco.
"We consider this as an extremely unfriendly step", the embassy said. "We urge the U.S. authorities to return our state symbols", the embassy added in a Twitter post.
"That is something that we take seriously".
Earlier this week, Moscow demanded that the United States returns the "illegally seized" diplomatic buildings.
In a telephone call with US Secretary of State Rex Tillerson, Mr Lavrov also criticised the "unacceptable" removal of Russian flags from the seized buildings.
In December 2016, two Russian diplomatic properties in NY and Maryland used by Russian diplomats were closed by the Obama administration over accusations of alleged Russian hacking during the presidential election.
Russian Federation did not immediately retaliate as the new Trump administration was taking office.
The latest flare-up comes as Jon Huntsman, Washington's new ambassador to Moscow, is preparing to assume his role.
The aggressive move prompted Moscow to force Washington to axe over 700 staff in Russian Federation.
The closures came in a dispute that also saw Moscow ordering Washington to reduce its diplomatic staffing in Russian Federation.
In reply, Russian Prime Minister Dmitry Medvedev blasted the motion as a declaration of a fully-fledged economic war, adding that barring a miracle, the law would have a decades-long negative effect on Russia-US relations.
"Yesterday, a new, I can officially say, hostile action of the USA authorities against our diplomatic institutions became known".