WASHINGTON — The sanctions demanded by U.S. officials in response to North Korea's announcement this week that it had tested a nuclear device would focus on closing pathways to proliferation of weapons technology.
But U.S. officials say any such effort would have to focus on the air and land routes through China and Russia that the government in Pyongyang has used in response to American monitoring on the high seas.
Since the 1990s, the Pentagon has used naval ships and aircraft to track and even intercept weapons shipments coming out of North Korea.
"Our folks pay very close attention to the vessels they are using and where they go; we stay on top of this one," Adm. William J. Fallon, the U.S. military's top officer in the Pacific, said last month. "One thing we can't do anything about is the air movement, because it goes over Chinese or Russian airspace. It's up to those countries to do things."
The new United Nations sanctions resolution proposed by the United States would direct all members "to undertake and facilitate inspection of cargo to or from" North Korea. In effect, it would require China to help close the gap in American efforts.
It's a challenge unlike any yet faced by U.S. diplomats and military officials. Until now, nations that have developed a nuclear capability have not viewed their new weapons as potential export commodities, as many believe Pyongyang does.
U.S. intelligence officials said Tuesday that they were still collecting data on Monday's declared blast, and knew little about the device involved. One military official said the Pentagon was awaiting data from its lone WC-135 "sniffer" aircraft, which was stationed at Kadena Air Base in Japan at the time of the North Korean test.
At the U.N., Chinese and Russian diplomats resisted tougher proposals by the Americans and Japanese, and U.S. Ambassador John R. Bolton dismissed a North Korean threat to launch a nuclear-tipped missile if Washington refused direct talks. Diplomats hope for a vote on a response to North Korea by Friday.
Past international efforts to block exports and enforce embargoes have had limited and short-lived success. But North Korea's use of Chinese routes for conventional weapons exports raises the concern that it may attempt to use similar means to transship nuclear technologies.
