The Air Force general in charge of the military’s homeland defense said she would use any additional money provided by Congress for upgrading radar to give advanced warning of the North Korean missile threat.

“Amidst an unprecedented pace of North Korean strategic weapons testing, our ability to provide actionable warning continues to diminish,” Gen. Lori Robinson, commander of U.S. Northern Command, told the Senate Armed Services Committee last Friday in written testimony.

“North Korea’s closed society and robust denial and deception capabilities challenge our ability to observe missile and nuclear test preparations, a concern that would be exacerbated in crisis or in wartime and complicate our ability to defend the United States,” she said.

Robinson, who doubles as commander of North American Aerospace Defense Command (NORAD), said she is “extremely confident” that existing U.S. hit-to-kill, anti-missile defenses would successfully intercept a North Korean Intercontinental Ballistic Missile (ICBM), but she expressed concerns about North Korea switching from liquid to solid-fuel rockets.

Solid-fuel rockets require less time in preparation before launch, she said. When asked what NorthCom would do with the money if given an additional $1 billion, Robinson said she would spend it on “putting the right radars in the right place. That’s where I would go first.”

Robinson said NorthCom is “on track to deploy the Long Range Discrimination Radar (LRDR). This critical midcourse sensor will improve persistent coverage of the United States and improve our target tracking and discrimination capability against potential countermeasures.”

In 2015, the Defense Department awarded a $784 million contract to Lockheed Martin for LRDS to discriminate between warheads and decoys.

North Korean leader Kim Jong Un has made no secret of his intention to build and test a solid-fuel ICBM with a nuclear warhead capable of hitting the U.S. mainland. On Feb. 11, North Korea announced that it had successfully tested a new ballistic missile powered by solid fuel.

The North Korean threat was one of the main topics of talks last week between Chinese President Xi Jinping and President Donald Trump at Trump’s Mar-a-Lago estate in Florida.

On Saturday, Adm. Harry Harris, commander of U.S. Pacific Command, ordered the carrier Carl Vinson and its battle group to cancel port visits to Australia and return to Western Pacific waters.

In her first testimony to the committee, Robinson, the first woman to lead a U.S. combatant command, warned that NorthCom and NORAD are operating “in a strategic environment that is as ambiguous and dangerous as any in our recent history. Threats to the United States and Canada are increasingly global, transregional, all-domain, and multi-functional in nature.”

“Russia, China, North Korea, Iran and non-nation-state violent extremist forces are capable of varied attacks against North America in multiple domains, from multiple approaches, and at increasingly greater ranges,” she said, but the North Korean threat is of particular concern.

Last year was one of “North Korea’s most active years in terms of nuclear weapon and missile program development in pursuit of weaponizing a nuclear ballistic missile capable of reaching the United States,” Robinson said.

“Pyongyang completed its fourth and fifth nuclear detonations, as well as its second consecutive successful satellite launch using an intercontinental ballistic missile-class booster, and conducted the nation’s first successful tests of an intermediate-range ballistic missile and a submarine-launched ballistic missile,” she said.

However, “I am confident in our ability to employ the Ground-based Midcourse Defense element of the Ballistic Missile Defense System to defend the homeland against a limited long-range ballistic missile attack from North Korea,” Robinson said.