MOSCOW, April 28. /TASS/. Another US-made Patriot surface-to-air missile system has entered combat duty in Ukraine, Ukrainian Air Force Commander Nikolay Oleshchuk said on Thursday.

"The second battery of Patriot SAMs is already on duty," the official wrote on his Telegram channel, posting a photo of a Patriot launcher.

Oleshchuk said on April 21 that the first Patriot battery is already being used by the pro-Kiev forces. Deputy Defense Minister Alexander Pavlyuk said the Kiev government has already received Patriot missile systems from the United States, the Netherlands and Germany.

Moscow has repeatedly warned Washington against transferring such weapons to Ukraine. On December 14, Kremlin Spokesman Dmitriy Peskov said that the Patriots would become a legitimate target of the Russian armed forces if they were supplied to Kiev.

The Patriot is a surface-to-air missile system which has been used in the United States since the 1980s. The Patriot systems, manufactures by the Raytheon corporation, are capable of hitting planes, drone, cruise missiles, shorter-and intermediate-range missiles. One battery consists of from five to eight mobile units. The platform can hold launch containers for 4 or 16 missiles depending on the modification.