WASHINGTON (AP) – Results from an initial air sampling after North Korea’s announced nuclear test showed no evidence of radioactive particles that would be expected from a successful nuclear detonation, an American government intelligence official said Friday.

The test results do not necessarily mean the North Korean blast was not a nuclear explosion, the official said, speaking on condition of anonymity because he was not authorized to disclose the sampling results.

The official described the results as the State Department announced that Secretary Rice will travel to China, South Korea and Japan next week to discuss steps to be taken to pressure North Korea to drop its nuclear efforts and to assess the security situation in the region.

Ms. Rice’s trip is the next step in the American diplomatic offensive at the United Nations and with Pyongyang’s neighbors.

Members of the U.N. Security Council agreed Friday on the wording of a resolution that would clamp sanctions on the communist country. The draft, which American officials said they hoped would be approved on Saturday, would authorize non-military sanctions against the North, and says that any further action the council might want to take would require another U.N. resolution.

It also eliminates a blanket arms embargo from a tougher, previous draft, instead targeting specific equipment for sanctions including missiles, tanks, warships and combat aircraft.

State Department spokesman Sean McCormack said that on Ms. Rice’s trip, “she’s going to be talking about the passage of that resolution certainly, but really what comes after. She’s going to be talking about how to go about actually implementing that resolution.”

The American government remains uncertain of the nature of the underground explosion Monday trumpeted by North Korea as a nuclear test. The air sampling tends to reinforce earlier doubts about whether the test blast was entirely successful, officials said. Data from seismic sensors indicated the explosion was smaller than expected.

At the White House, press secretary Tony Snow said the Bush administration’s analysis of North Korea’s claim was still ongoing and is covering a wide range of data in an attempt to reach a conclusion about whether it is valid.

“We still do not have a definitive statement on it,” he said. “They still think the analysis that they’re doing will take another day or two.”

The air sample was taken Tuesday by a specialized aircraft, the WC-135, flying from Kadena air base in Okinawa, Japan. It apparently took the sample over the Sea of Japan, between the Korean mainland and Japan.

In Beijing, a government official said Friday that Chinese monitoring also has found no evidence of airborne radiation from the test-explosion. The official with the State Environmental Protection Administration said China has been monitoring air samples since Monday.

“We have conducted air monitoring and found no radiation in the air over Chinese territory so far,” said the official, who requested anonymity because he was not authorized to publicly release the information. The official declined to explain how the Chinese monitoring was conducted.

The American intelligence official said an initial result from testing of the air sample became available late this week. He said a final result would be available within days but the initial finding is considered conclusive.

It was not immediately clear whether the WC-135 took additional samples after the Tuesday effort.

America, which has sought tough steps in the United Nations that could leave the door open to a blockade or other military action, has had to give ground to gain support from China and Russia. Those countries, along with South Korea, have been reluctant to abandon diplomatic efforts to resolve the standoff.

On Wednesday, Mr. Bush indicated that he saw little distinction between an actual nuclear test by North Korea and its announcement of one.

“The United States is working to confirm North Korea’s claim, but this claim itself constitutes a threat to international peace and stability,” Mr. Bush said.