A State Department official said Friday that the United States had concerns about Syria’s involvement in illicit nuclear activities and suggested that North Korea might be aiding the Syrians in their efforts.

Andrew Semmel, a top official on countering the spread of nuclear weapons, said that Syria may have a number of “secret suppliers” for a covert nuclear program, and that North Korean technicians were currently operating inside Syria.

His comments, in an interview with The Associated Press in Rome, came in response to questions about an Israeli airstrike inside Syria last week. Neither Israel nor the United States has confirmed what targets the Israeli jets hit, and the government in Jerusalem has imposed a blanket restriction on the Israeli news media from reporting details about the raid.

American officials have been similarly tight-lipped, and officials who ordinarily see intelligence reports on such issues say their access has been restricted.

Mr. Semmel did not specify whether the technicians in Syria were specialists in nuclear technology; North Korea has long supplied Syria with missile technology. Some weapons experts said they were skeptical that Syria was in league with North Korea to build a secret program.

Damascus is not thought to have made serious efforts in the past to develop nuclear weapons, and those experts said it was unlikely that the Syrians could afford such a program or had the technical expertise to sustain it.

The speculation about possible North Korean activities inside Syria is heightening the Bush administration’s concern about the future of its diplomatic efforts to dismantle North Korea’s nuclear program. The Bush administration’s top negotiator for North Korea, Christopher R. Hill, said that the United States still planned to go ahead with an agreement for food and fuel aid to North Korea in exchange for its decision to dismantle its nuclear program.

“We’ve always been concerned about the issue of proliferation,” Mr. Hill told reporters during a news conference at the State Department. “To me, this simply is an important reminder of the need to accelerate the process which we’ve already engaged in, to achieve denuclearization of the Korean Peninsula.”

He declined to say whether the United States had sought a specific explanation from North Korean officials, and added that the issue “does not change the goal of what we’re aiming for.”

A Bush administration official said earlier this week that over the past several weeks, Israel had conducted several aerial surveillance flights over Syria to take pictures of what Israeli officials were said to believe could be possible nuclear development installations.

North Korea’s government took the unusual step of publicly condemning the Israeli strike. The Chinese state-run news agency Xinhua cited a North Korean Foreign Ministry official on Tuesday as calling the Israeli strike “a very dangerous provocation, little short of wantonly violating the sovereignty of Syria and seriously harassing the regional peace and security.”

Some who advocate a hard-line stance toward North Korea, including former top Bush administration officials, said that possible intelligence about North Korea’s efforts to aid Syria should halt diplomatic talks with Pyongyang.

“It would be a big mistake for the State Department to push ahead with the six-party process without this being resolved,” said John R. Bolton, a former United States ambassador to the United Nations, referring to the diplomatic talks with North Korea. “They are rushing to finish this and declare victory, which could be a catastrophe for the president.”

New York Times