The ballistic missile that North Korea launched over the weekend plunged into the sea some 300 miles away.
But the missile, which the country's state-run news agency claims can carry a nuclear warhead, could have traveled nearly four times as far, a South Korean lawmaker told NBC News on Tuesday.
"We confirm that the new type of ballistic missile launched by North Korea has a range of more than 2,000 kilometers, according to our intelligence agency," said Lee Cheol Woo, a ruling party lawmaker who serves as the head of the Intelligence Committee in the National Assembly.
South Korea's intelligence agency revealed that detail to lawmakers during a closed meeting.
Cheol Woo added that the missile — the first to be launched during Donald Trump's presidency — uses solid fuel and is an upgraded version of a submarine launched ballistic missile. It landed roughly 310 miles off South Korea's eastern coast.
The claim came as U.S. Ambassador to the United Nations Nikki Haley called on the U.N. to respond with unspecified "actions."
"We call on all members of the Security Council to use every available resource to make it clear to the North Korean regime — and its enablers — that these launches are unacceptable," she said in a statement. "It is time to hold North Korea accountable — not with our words, but with our actions."
The council released a statement Monday condemning the launch — and pointing out the country's history of nuclear and ballistic missile tests.
The missile was launched toward the Sea of Japan as that country's prime minister, Shinzo Abe, met with Trump at his Florida resort — a move South Korea's military described as a "show of force" to the new president.