WASHINGTON (AP) ― U.S. intelligence experts expect North Korea’s new young leader Kim Jong-un to continue Pyongyang’s policy of attempting to export its weapons systems.

Director of National Intelligence James Clapper told the Senate Intelligence Committee Tuesday that the North’s export of ballistic missiles and associated materials to countries including Iran and Syria illustrated the reach of its proliferation activities.

He also cited North Korea’s assistance to Syria in building a nuclear reactor, destroyed by Israel in 2007.

“We don’t expect Kim Jong-un, North Korea’s new young leader, to change Pyongyang’s policy of attempting to export most of its weapons systems,’’ Clapper told a hearing on worldwide threats.

Clapper said it was too early to assess the extent of Kim’s authority after his father Kim Jong-il died Dec. 17. That took the hereditary communist regime into a third generation but left uncertainty over whether the untested new leader could consolidate control. North Korea has a history of aggression against its southern neighbor, an important U.S. ally.

Clapper said senior regime leaders in North Korea probably would remain cohesive at least in the near term to prevent instability and protect their interests.

The Democratic chairwoman of the committee, Sen. Dianne Feinstein, said a recent classified intelligence briefing on the threat North Korea poses “was quite sobering.’’

“In North Korea there’s now a 28-year-old dictator ruling over the country’s cache of nuclear weapons and ballistic missiles which should concern us deeply,’’ she said.

North Korea has conducted two nuclear tests since 2006 and unveiled a uranium enrichment facility in late 2010 that could provide it another means of making fissile material for a weapon. It also has developed a ballistic missile that could potentially strike the United States. The North, however, also would need to be able to miniaturize a nuclear device to mount it on a missile.

Clapper said Pyongyang probably would not attempt to use nuclear weapons against the U.S. unless its regime was on the verge of military defeat and risked “irretrievable loss of control.’’