Soldiers fire the Patriot weapons system at the NATO Missile Firing Installation in Greece. [AP Photo]

The United States is preparing to send the Patriot missile defense system to Ukraine to shoot down incoming Russian missiles, a decision that could be announced as soon as this week, a U.S. defense official and a second U.S. official told VOA on Tuesday.

Both officials spoke on condition that they not be identified because the decision has not yet been formally announced. The decision was first reported by CNN.

Ukraine has asked its Western partners for air defenses, including the U.S.-made Patriot system, as Russia has used its missile arsenal along with newly acquired Iranian drones to target critical civilian infrastructure, including electrical power facilities needed to keep the population warm as temperatures fall.

Air Force Brigadier General Pat Ryder, the Pentagon press secretary, declined to comment on the Patriot battery transfer, saying he had "nothing to announce at this time."

"We'll continue to look at ways that we can best support Ukraine to protect their population and to protect their broader infrastructure to be able to survive these attacks," Ryder said.

The U.S. has provided Ukraine with billions of dollars in military support, including air defense weapons ranging from Stingers - a surface-to-air missile system light enough to carry - to the larger NASAMS anti-aircraft systems, which can provide air defense against short-to-medium-range targets.

But on Tuesday, Ukrainian air force spokesman Yuriy Ignat told reporters that Ukraine was still "not able to shoot down ballistic [missiles] by air defense means that we have in our arsenal."

"Therefore, the most effective method of destroying these missiles is at the launch, where they are," he added.

Analyst warns of 'limited return on investment'

NASAMS are designed to protect population centers from air-to-surface threats and can identify and target fixed and rotary-wing aircraft, cruise missiles, and drones. NASAMS, however, are not considered effective against ballistic missiles.

Retired Rear Admiral Mark Montgomery, a defense analyst with the Foundation for Defense of Democracies, acknowledged that Ukraine was "out of the kind of weapon needed" to defend against ballistic missiles but criticized the potential Patriot acquisition.

"Patriot is an extremely complex and expensive system to operate. Each round of Patriot is between $3 [million] and $4 million apiece. That is a very expensive system. It would use up a lot of the money being set aside for them, I think, with a very limited return on investment," he told VOA.

Montgomery also raised concerns that providing Patriots to Ukraine would drain from the Ukrainian military's already small batch of NASAMS operators.

Instead, he suggested sending more of the air defense weapons that Ukraine is already receiving and using to great effect, or perhaps providing Ukraine with the Counter-Rocket, Artillery, Mortar (C-RAM) system that the U.S. has used in the Middle East.

"For me, Patriot is not a great answer.," he said. "More NASAMS, more S-300s, you know, more cowbell."