Zelensky said Ukraine had received the National Advanced Surface-to-Air Missile Systems (NASAMS) from the U.S., systems that he had been lobbying for during previous pleas for international help with military aid and equipment.

In addition to the NASAMS, Zelensky said Ukraine was in need of HIMARS (High Mobility Artillery Rocket Systems), artillery as well as air defense systems.

“We absolutely need the United States to show leadership and give Ukraine the air defense systems,” Zelensky said on Sunday. “I want to thank President Biden for a positive decision that has been already made. And to the U.S. Congress, we received NASAMS. It’s the air defense systems.”

What are NASAMS?

NASAMS are medium-range air defense systems designed to identify and destroy aircraft, cruise missiles and unmanned aerial vehicles (UAVs). They are usually used to protect key strategic assets or civilian populations.

The system was developed by Kongsberg, a defense and aerospace firm based in Norway, in partnership with the U.S. defense giant Raytheon. Work on the project began in the 1990s and it entered full Norwegian service in 1998.

According to the two companies, the system has been helping to protect Washington D.C. from aerial threats since 2005.

Raytheon says it “provides air defenders with a tailorable, state-of-the-art defense system.”

U.S. defense officials said the NASAMS will help to protect Ukraine against a range of aerial threats from Russia.

“NASAMS are just the latest in the diverse set of air defense capabilities we are delivering to Ukraine,” William LaPlante, undersecretary of defense for acquisition and sustainment, said on August 31. “These are proven systems that will make a real difference in the battlefield.”

Why Ukraine wants them

Kyiv had desperately lobbied for the technology as Ukraine tries to repel Russia’s invasion, which began in February. President Joe Biden approved the NASAMS shipments to Ukraine at the end of August.

“I’m so thankful for the people… for the U.S. Congress, to President Biden, that you work on this issue. And I also would like to see this issue supported,” Zelensky said.

But he added that the NASAMS defense system was still not enough to help cover all the areas he needed. “Believe me, it’s not even nearly enough to cover the civilian infrastructure, schools, hospitals, universities, homes of Ukrainians,” he said.

Zelensky asked for continued help, arguing that winning the war would make Ukraine safer for its refugees to return home and would enable the country to rebuild itself meaning it would no longer be reliant on U.S. aid.

“Why do we need this? We need the security in order to attract our Ukrainians to come back home. If it’s safe, they will come, settle, work here and will pay taxes and then we won’t have a deficit of $5 billion in our budget,” Zelensky said. “So it will be a positive for everybody. Because as of today, the United States gives us $1.5 billion every month to support our budget to fight, fight this war. However, if our people will come back- and they do want to come back very much, they have a lot of motivation- they will work here.”

“And then the United States will not have to continue [to] give us this support,” Zelensky continued. “I’m sorry, I’m using this language about the war, but it will be a win-win for everybody. For the United States, it will be significant savings, but for us, it will be an opportunity to secure our territory and make it safe for our population.”

It is unclear whether Ukraine will receive another shipment of NASAMS and how many the country will receive in total.

Ukraine has staged a series of successful counter-offensives in recent months, while Russia has been forced to implement a partial mobilization to send more troops to the front line.

Newsweek has reached out to Russia’s Foreign Ministry and Ukraine’s Ministry of Defense for comment.

Update 09/26/2022, 2 p.m. ET: This article was updated with additional information on NASAMS and its capabilities