* Panetta declines to detail support due to 'sensitivity'
* Military, economic ties with China date back decades
* Says recent provocations followed some recent progress
WASHINGTON, April 19 (Reuters) - China has provided some assistance to North Korea's missile program, U.S. Defense Secretary Leon Panetta said on Thursday, a week after the hermit state's failed missile launch triggered broad international condemnation.
"I'm sure there's been some help coming from China. I don't know, you know, the exact extent of that," Panetta told members of the House Armed Services Committee when asked whether China had been supporting North Korea's missile program through "trade and technology exchanges."
North Korea's powerful Asian neighbor is the hermit kingdom's only major ally, with military and economic ties that date back to the communist origins of the two nations.
On Wednesday, Pyongyang said it was ready to retaliate in the face of widespread condemnation of the failed launch, increasing the likelihood the isolated state will go ahead with a third nuclear test.
After last week's launch, which the United States said was a disguised long-range missile test but which Pyongyang insists was meant to put a satellite into orbit, the Obama administration said it had suspended a food aid deal.
China, Pyongyang's main economic and diplomatic backer, has called for "dialogue and communication" as tensions with North Korea mount.
In Thursday's hearing, Republican Rep. Michael Turner pressed Panetta about a transporter launcher system - essentially a large truck on top of which a missile is mounted - that North Korea showcased dur ing a military parade on Sunday, wh ich he said appeared to be made in China.
Panetta declined to give additional details about any Chinese support for North Korea's missile capabilities in a public setting due to "the sensitivity of that information."
"But clearly there's been assistance along those lines," the Defense Secretary said.
Panetta said there was "no question" North Korea's efforts to develop long-range missile and nuclear weapon capability were a threat to the United States. "For that reason we take North Korea and their provocative actions very seriously," he said.
"And China ought to be urging them to engage in those kinds of ... diplomatic negotiations. We thought we were making some progress and suddenly we're back at provocation," he added. (Reporting By Missy Ryan; editing by Todd Eastham)