The Russian flag waves in the wind on the rooftop of the Consulate General of Russia in San Francisco, California, U.S., September 2, 2017. (REUTERS PHOTO)

Russia told U.S. authorities it strongly protests against the removal of Russian flags from its shut-down diplomatic properties, the Russian Foreign Ministry said Thursday.

"We consider this incident as a desecration of the Russian state symbols," the ministry's spokeswoman Maria Zakharova said at a news briefing.

She said that agents of U.S. special services removed Russian flags from the Russian trade mission in Washington and the Consulate General in San Francisco, which were seized by the U.S. authorities in September in a series of tit-for-tat actions that form part of the spat between the two countries.

Zakharova said that Moscow considered the removal of its flags as a "hostile step" and was thinking new measures in response to it.

She said that by breaking into the Russian diplomatic properties, the U.S. special services showed that they were ready for Moscow to act in a similar manner.

Zakharova also said that in accordance with an instruction given by President Vladimir Putin, the Russian Foreign Ministry was in the process of selecting a legal firm to start a court proceeding over the seizure of diplomatic properties.

In December 2016, two Russian diplomatic properties in New York and Maryland used by Russian diplomats were closed by the Obama administration over accusations of alleged Russian hacking during the presidential election.

Russia has drastically scaled down the U.S. diplomatic staff in Russia to 455 people and seized a U.S. dacha and a warehouse in Moscow in retaliation to Washington's actions.