A Russian flag flies next to the US embassy building in Moscow on March 27, 2018. (Xinhua/AFP)

MOSCOW, Aug. 17 (Xinhua) -- Russia has sent a note of protest to the U.S. State Department over Washington's continuing breach of international law with regard to Russian diplomatic and consular missions in the U.S. territories, the Russian Foreign Ministry said Friday

"The Ministry of Foreign Affairs of the Russian Federation has lodged a strong protest with the State Department by sending an appropriate note through diplomatic channels," the ministry said in a press release.

It also drew the attention of UN Secretary-General Antonio Guterres to this matter by sending a letter earlier in May for the purpose of preparing the report of the 73rd session of the UN General Assembly, the ministry added.

Russia and the United States have been waging sanctions against each other in the diplomatic sphere as bilateral relations have continued to worsen over recent years.

In December 2016, Washington closed Russian diplomatic compounds in New York and Maryland.

In July 2017, Russia declared its decision to cut the number of U.S. diplomatic staff and seize two U.S. properties in Moscow.

In September 2017, U.S. authorities shut down the Russian Consulate General in San Francisco and trade missions in Washington D.C. and the New York City.

In March, Russia declared its decision to expel 60 U.S. diplomats and shut the U.S. consulate general in St. Petersburg in response to Washington's moves against Moscow.

Moscow has repeatedly said that it reserves the right to take additional countermeasures against U.S. diplomatic properties in Russia if Washington continues hostility.