The US military on Wednesday signed a $1.2 billion contract with Raytheon Technologies for six NASAMS air defense systems to be sent to Ukraine, the Pentagon announced, Reuters reported.

The United States has approved sending a total of eight NASAMS missiles to Ukraine to repel Russian missile and drone attacks.

Ukraine received the first two air defense systems of NASAMS in November. Others will be delivered in the coming months as they are built.

“NASAMS is just the latest in a diverse array of air defense assets that we are providing to Ukraine,” said Bill LaPlante, US Under Secretary of Defense for Acquisition and Sustainment.

According to an Army statement, the six NASAMS systems were part of the fifth package of the Ukraine Security Assistance Initiative, which was announced on August 24 and had a total cost of $2.98 billion.

Funds from the initiative allow the Biden administration to purchase weapons from industry, rather than taking weapons from existing U.S. stockpiles.

The contract covers NASAMS batteries, training and logistical support for the Ukrainian military and security forces.

Funding for the other two NASAMSs came from the initiative’s third package announced in July.

Last week, Doug Bush, the head of the U.S. Army’s acquisition division, told reporters that the U.S. military is speeding up the arms procurement process to expedite the completion of pending contracts needed to replenish U.S. arms stocks depleted by arms shipments to Ukraine.

The Pentagon said that the new NASAMS air defense systems provided by the United States have so far had a 100 percent success rate in intercepting Russian missiles in Ukraine.

In total, since the beginning of the Biden administration, the United States has allocated more than $19.3 billion in security assistance to Ukraine.