(NewsNation) — The Biden administration has authorized more than $2 billion in security aid for Ukraine as the Russian invasion of Ukraine stretches into its second month.

The Biden administration has authorized $2 billion in security aid for the Eastern European country since last year, with more than $1 billion of that given throughout the course of a week in March, according to the administration.

Some of the March package included 800 anti-aircraft systems, 20 million rounds of ammunition and 9,000 anti-armor systems, including high-accuracy shoulder-mounted missiles.

These weapons are coming from existing U.S. stockpiles in Europe and then flown to Poland or Romania before being shipped to western Ukraine.

Ukraine does not pay for these weapons since they are donated by other countries. The European Union, for example, announced it is purchasing and delivering weapons for the first time ever in its history. In total, 25 different nations signed up to purchase and deliver weapons to Ukraine.

In the past, Ukraine has purchased weapons from other nations to assist their war efforts in the Donbas.

For example, the Trump administration sold $47 million worth of missiles and launchers in 2017. But a large chunk of the weapons Ukraine has received over the last eight years are donations given as a part of security aid.

Congress has already approved $13.6 billion in military and humanitarian aid for Ukraine, and the security aid will come from that allotment, which is part of a broader bill that Biden signed into law earlier this month.

The Biden administration has also provided specific assistance for humanitarian efforts, development and democracy throughout Ukraine and the surrounding region.