The US is planning to send Patriot air defense missiles to Ukraine, US media reports say. President Joe Biden is likely to announce the move this week, according to unnamed officials. Ukraine has been requesting further air defense support for some time, as Russian attacks have continued to kill civilians and cause major blackouts. Patriot is one of the most advanced US air defense systems but supplies to Ukraine are likely to be limited. It is not known how many of the batteries will be sent to Ukraine. Once the move is approved, the systems are likely to be sent over in the coming days, with Ukrainian soldiers trained to use them at a US Army base in Grafenwoehr, Germany, the outlet added. The Patriot system would be a legitimate target for Russian strikes, the Kremlin said on Wednesday. The news came as explosions rocked the Ukrainian capital Kyiv, in the latest of a steady stream of attacks by Russia. Moscow has repeatedly targeted Ukrainian energy infrastructure since October. Ukraine has been asking the US for more air defense support for months. US national security spokesman John Kirby said last week that Russia and Iran’s relationship had warmed to a fully fledged defense partnership. Patriot has been described as the most advanced air defense system the US possesses. Each missile costs about $3m (£2.4m), the Washington Post reported in 2017. The systems have been bought by more than a dozen countries since they came into use in the 1980s, and are in use by US allies in the Pacific and Europe, as well as Saudi Arabia. The battery includes the missile launcher, a radar, command and control center, and other support vehicles, and needs a large team to operate and maintain it. — BBC