National Intelligence director James Clapper said Tuesday that the U.S. goal of persuading North Korea to abandon its nuclear weapons is probably a “lost cause” and the best hope is to cap its capability.

Clapper’s comments come amid mounting concern that the North is moving closer toward having a nuclear-tipped missile that could reach the American mainland. It has conducted two atomic test explosions this year and more than 20 ballistic missile tests.

The State Department said Tuesday there had been no change in policy. U.S. administrations have long demanded that North Korea agree to denuclearization, although aid-for-disarmament negotiations have been stalled for years and sanctions have failed to stop the North’s weapons’ programs.

Clapper said that while North Korea has yet to test its KN-08 intercontinental ballistic missile, the U.S. already operates on the assumption that Pyongyang potentially has the capability to launch a missile that could reach parts of the United States, particularly Alaska and Hawaii.

“I think the notion of getting the North Koreans to denuclearize is probably a lost cause,” Clapper said at the Council on Foreign Relations in New York. He added that the best the U.S. could probably get is some kind of a cap on North Korea’s nuclear capabilities.

“They are under siege and they are very paranoid, so the notion of giving up their nuclear capability, whatever it is, is a nonstarter with them,” he said.

State Department spokesman John Kirby said he had not seen Clapper’s comments but said the U.S. still aims for a resumption of six-nation aid-for-disarmament negotiations that have been stalled since the North pulled out of the talks in 2009.

“We want to continue to see a verifiable, denuclearization of the peninsula. We want to see a return to the six-party talk process, and that means we need to see the North show a willingness and an ability to return to that process which they haven’t done yet,” Kirby told reporters in Washington.

In the meantime, the Obama administration says it is intent on tightening sanctions on the government of young leader Kim Jong Un, who has doubled down on increasing the North’s nuclear arsenal. In addition to its nuclear and missile tests this year, North Korea is also believed to producing more fissile material for bombs. U.S. experts estimate that North Korea has 13 to 21 nuclear weapons, and could have as many as 100 by 2020.

Separately Tuesday, Scott Busby, a senior State Department official for human rights, criticized China’s implementation of U.N. sanctions against North Korea that are intended to starve it of revenue for its development of weapons of mass destruction.

Busby, who was speaking at a Washington think tank, said that China’s use of a loophole in the sanctions to purchase huge amounts of North Korean coal is “unacceptable.” He said coal sales are probably the North’s main source of foreign currency.

He said the No. 2 U.S. diplomat, Antony Blinken, will raise that issue when he meets this week with Chinese officials in Beijing.

The U.S. wants China to agree to tighter U.N. sanctions on North Korea in response to a Sept. 9 nuclear test explosion and enforce restrictions already in place.

Busby credited China with a “slight improvement” in its treatment of North Korean asylum seekers who escape across the northern border into China. But he added that China is still repatriating significant numbers of them back to the North.

(AP)