He cautioned that North Korean leader Kim Jong Un was not likely to stop with the development of a single missile.
"The logical next step would be to develop an arsenal of weapons," Pompeo said.
He added that the Administration was focused on a policy of denying North Korea the ability to do so, but he declined to offer policy prescriptions or say whether the United States was prepared to launch a preemptive military strike.
Pompeo affirmed that the CIA has concluded that Kim is a "rational actor". But he questioned whether the North Korean leader was getting a full, accurate picture on crucial issues, including the dire state of his own economy, from his retinue of senior advisers.
North Korea's nuclear weapons programme has consumed much of the Trump Administration's foreign policy focus in its first year and prompted bellicose statements from the President. Earlier this month in a Twitter message, Trump bragged that his "Nuclear Button" was "much bigger & more powerful" than Kim's, "and my Button works!"
The President's remarks indicated that he thinks North Korea has yet to field reliable nuclear weapons that can hit US targets.
US officials have concluded that North Korea would be able to field a reliable, nuclear intercontinental ballistic missile as early as this year
US officials have concluded that North Korea would be able to field a reliable, nuclear intercontinental ballistic missile as early as this year, and that the country has already produced a miniaturised nuclear warhead that can fit inside its missiles - a key milestone in becoming a fully capable nuclear power.
Pompeo credited the CIA with improving its intelligence-gathering in other areas on North Korea, long considered one of the most opaque regimes in the world. Over the past year, he said, the agency has helped to interdict shipments of goods into North Korea that are banned under United Nations sanctions.
Pompeo didn't cite specific examples. But last September, a senior Treasury Department official told Congress that North Korea uses deceptive practices, such as falsifying shipping vessel documents, to illicitly bring luxury goods and staples, such as coal, into the country from China and Russia.