WASHINGTON — U.S. President Donald Trump criticized Seoul on Tuesday for failing to finance the U.S. deployment of a missile defense system on the Korean Peninsula.

Last year, the U.S. deployed two Terminal High Altitude Area Defense, or THAAD, launchers to South Korea in response to North Korea's increased missile and nuclear tests.

"I said, so let me get this, we have a system that's very expensive and we shoot down rockets that are shot from North Korea to South Korea," Trump said to a crowd in Council Bluffs, Iowa. "Okay, so we're protecting South Korea, right? Why aren't they paying?"

Trump added that he asked a "certain general" about THAAD's price tag and was told that because South Korea is an ally the United States foots the bill.

"Then I said, all right, give me the bad news. Raytheon, give me the bad news. How much is it going to cost?" Trump said referring to the defense company that produces the radar for THAAD. The missile system itself is made by Lockheed Martin.

"Sir, $1 billion.' I said, 'whoa, whoa!' So we're putting in a system that we pay for and it's going to cost a billion in order to protect an immensely wealthy country [South Korea] that makes all of your television sets, right?'" Trump said.

In addition to protecting the region, the U.S. currently has approximately 28,500 troops stationed in South Korea, a legacy of the Korean War, which halted in 1953 in an armistice that left the two Koreas technically still at war.