The Biden administration is finalizing plans to send the Patriot missile defense system to Ukraine that could be announced as soon as this week, according to two US officials and a senior administration official, writes CNN.

The Pentagon’s plan still needs to be approved by Defense Secretary Lloyd Austin before it is sent to President Joe Biden for his signature. The three officials told CNN that approval is expected.

Ukraine has been calling for the US to send the advanced long-range air defense system that is highly effective at intercepting ballistic and cruise missiles as it comes under a barrage of Russian missile and drone attacks that have destroyed key infrastructure across the country. It would be the most effective long-range defensive weapons system sent to the country and officials say it will help secure airspace for NATO nations in Eastern Europe.

It is not clear how many missile launchers will be sent but a typical Patriot battery includes a radar set that detects and tracks targets, computers, power generating equipment, an engagement control station and up to eight launchers, each holding four ready to fire missiles.

Once the plans are finalized, the Patriots are expected to ship quickly in the coming days and Ukrainians will be trained to use them at a US Army base in Grafenwoehr, Germany, officials said.