This month a new radar of the Voronezh class will be put on alert duty near Russia’s second largest city of St. Petersburg as part of Russia’s early warning system, a missile defense spokesman said on Thursday.

The current overhaul of Russia’s missile defenses is also due to the new strategic challenges presented by the U.S.-led missile shield plans in Europe.

“New generation missile warning radar in the Leningrad Region will be put on alert duty in February 2012,” said Col. Alexei Zolotukhin, spokesman for the missile defense troops in the Russian Defense Ministry.

The radar in the Leningrad Region was built in 2006 and until recently was operated in a test mode, he said.

Two other Voronezh class radars are already operating in a test mode in Armavir in the Black Sea area and in Pionersky near Russia's westernmost exclave of Kaliningrad. Another one near the Siberian city of Irkutsk will be put into test mode operation later this year.

The Voronezh class radars are a serious breakthrough compared to the previous generation radars of the Dnepr and Daryal class. The radar in Pionersky has a range of 6,000 kilometers and can simultaneously track around 500 objects.

Under the national defense program until 2020, the Defense Ministry is to replace all Soviet long-range radars and close all gaps in radar coverage on Russia's borders.