WASHINGTON (Yonhap News) -- North Korean leader Kim Jong-il could attempt further provocations to boost the standing of his heir-apparent son, the top U.S. intelligence official predicted Thursday, saying the regime‘s deadly attack on a South Korean island was believed to be part of such efforts.

Director of National Intelligence James Clapper said in written testimony to the House Intelligence Committee that the November shelling of the South’s border island of Yeonpyeong “was meant in part to continue burnishing successor-designate Kim Jong-un‘s leadership and military credibility among regime elites.”

“Kim Jong-il may feel the need to conduct further provocations to achieve strategic goals and portray Jong-un as a strong, bold leader, especially if he judges elite loyalty and support are in question,” he said.

The North’s leader has stepped up preparations to bequeath power to the youngest son still believed in his 20s.

In September, the totalitarian regime made the junior Kim a four-star general and gave him high-level posts in the ruling Workers‘ Party. The moves represented the North’s first concrete steps to put the inexperienced son in line to take over the family dynasty.

The DNI chief said, however, that the “succession process is still subject to potential vulnerabilities, especially if Kim Jong-il dies before Jong-un consolidates his authority.”

On the North‘s nuclear capabilities, Clapper said that the communist regime is believed to have tested two nuclear devices. It is still unclear “whether the North has produced nuclear weapons, but we assess it has the capability to do so.”

Fueling concern about the North’s nuclear capabilities were Pyongyang‘s revelations in November that it has a uranium enrichment facility at the country’s main Yongbyon nuclear complex.

Uranium, if highly enriched, can be weapons-grade, providing the regime with a second way of building atomic bombs after the existing plutonium-based program.

Clapper said the North must have been seeking uranium enrichment for an “extended period of time.”

“If so, there is clear prospect that DPRK has built other uranium enrichment-related facilities in its territory, including likely R&D and centrifuge fabrication facilities, and other enrichment facilities,” he said.

In recent months, North Korea has indicated a growing willingness to return to the nuclear negotiating table, reversing its previous stance that it will never come back to the six-party nuclear talks that were last held in December 2008.

“The North probably wants to resume nuclear discussions to mitigate international sanctions, regain international economic aid, bolster its ties with China, restart bilateral negotiations with South Korea and the United States, and try to gain tacit international acceptance for its status as a nuclear weapons power,” the U.S. spy chief said.