The Pentagon's move to shift $416 million into missile defense will help jumpstart the construction of new interceptors in Alaska to counter North Korea, Sen. Dan Sullivan, R-Alaska, said Friday.

The senator said $81 million of the repurposed money will help fund the increase from 44 to 64 ground-based missile interceptors at Fort Greely, one of two sites on the West Coast prepared to shoot down an attack from North Korea. Another $47 million will be used on silos.

The Pentagon quietly filed a request with Congress to shift the money from other areas of its budget in September, and both Joint Chiefs chairman Gen. Joseph Dunford and Defense Secretary Jim Mattis teased the move in congressional testimony.

"With these additions — and others — to our nation's missile defenses, [North Korean leader] Kim Jong Un should know that we will shoot down any nuclear ICBM that threatens our citizens, our troops, or our allies," Sullivan said in a released statement.

North Korea has twice tested intercontinental missiles since July and conducted another nuclear test a month ago, raising concerns among military leaders and Capitol Hill lawmakers over whether the U.S. is doing enough to protect against the threat.

Sullivan also spearheaded legislation in the Senate's recently passed National Defense Authorization Act that boosts missile defense by $630 million and bolsters the ground-based interceptors and funds development of space-based sensors to better track incoming ballistic missiles.

"While these initial missile-defense funds are critical, we must do much more," Sullivan said. "President Trump promised that he would add ‘billions of dollars' to missile defense."

But that pledge has yet to materialize, he said.