Defense Secretary Robert M. Gates warned North Korea on Saturday that the United States would not accept it as a nuclear weapons state and would consider any transfer of nuclear material to other countries or terrorist groups a "grave threat" to the United States and its allies.
"We will not stand idly by as North Korea builds the capability to wreak destruction on any target in the region - or on us," Mr. Gates told a major security conference here that has been dominated by North Korea's test this week of a nuclear device and the firing of at least six short-range missiles, all in defiance of international sanctions. North Korea test-fired a missile on Friday, according to a South Korean defense official.
North Korea, Mr. Gates said, had a choice: "To continue as a destitute, international pariah, or chart a new course."
Mr. Gates, who was speaking for the first time at the annual conference, called the Shangri-La Dialogue, as an emissary of his new commander in chief, said the new administration had limited patience with North Korea's bellicose words and behavior.
"President Obama has offered an open hand to tyrannies that unclench their fists," Mr. Gates said. "He is hopeful, but he is not naïve. Likewise, the United States and our allies are open to dialogue, but we will not bend to pressure or provocation."
Military officials traveling with Mr. Gates said the tough talk was aimed at increasing worldwide pressure on North Korea as well as reassuring allies in the region, particularly Japan and South Korea, that the United States was committed to their defense should North Korea make good on talk of war this week. On Wednesday, North Korea threatened military strikes against the South.
The officials acknowledged that the United States had only limited information about what was happening inside North Korea and suspected but did not know for certain that its leader, Kim Jong-il, was in the midst of political maneuvers to make his youngest son, Kim Jong-un, his successor. The officials described the country's leadership as unpredictable and bizarre.
Mr. Gates's sharp language was met with some skepticism by at least one participant in the conference, a Hong Kong television commentator, who in a question-and-answer session after the defense secretary's formal remarks noted that although Mr. Gates had declared that the United States would not recognize North Korea as a nuclear weapons state, it was already a "de facto nuclear weapons state." The questioner asked about the next step for the United States and whether the long-running six-nation talks aimed at getting North Korea to abandon its nuclear program had failed.
Mr. Gates responded that the next step was political and that the United States would send a team to Asia to "reassess" how to go forward with the talks. He acknowledged, "It would be hard to point to them at this point as an example of success."
Although North Korea was the "hot topic" at the conference, as Mr. Gates put it to reporters on his plane, he also used the forum to appeal to Asian allies for help, both financial and military, with the war in Afghanistan.
"I know some in Asia have concluded that Afghanistan does not represent a strategic threat to their countries, owing in part to Afghanistan's geographic location," Mr. Gates said. "But the threat from failed or failing states is international in scope."
In representing Mr. Obama, Mr. Gates concluded that the United States, "in our efforts to protect our own freedom, and that of others" had "from time to time made mistakes, including at times being arrogant in dealing with others."
He did not name names, but then said, "We always correct our course."