Secretary of State Rex Tillerson said “global action is required to stop a global threat,” referring to North Korea's Tuesday launch of an intercontinental ballistic missile.

WASHINGTON — North Korea’s first test of an intercontinental ballistic missile, demonstrating a dangerous new reach for weapons it hopes to top with nuclear warheads one day, is spurring U.S. demands for “global action” to counter the threat.

U.S. officials confirmed Tuesday their belief that North Korea’s latest missile launch was indeed an ICBM and joined South Korea and Japan in requesting an emergency meeting of the U.N. Security Council, scheduled today. Previously, North Korea had demonstrated missiles of short and medium range but never one able to get to the United States.

In a show of force directly responding to North Korea’s provocation, U.S. and South Korean soldiers fired “deep strike” precision missiles into South Korean territorial waters on Tuesday, U.S. military officials in Seoul said. The missile firings demonstrated U.S.-South Korean solidarity, the U.S. Eighth Army said in a statement.

Secretary of State Rex Tillerson vowed “stronger measures to hold the DPRK accountable,” using an acronym for the isolated nation’s formal name, and said: “Global action is required to stop a global threat.” Any country helping North Korea militarily or economically, taking in its guest workers or falling short on Security Council resolutions, he said, “is aiding and abetting a dangerous regime.”

Tillerson’s statement, issued Tuesday evening, notably did not mention China, whose help the Trump administration has been aggressively seeking to press Pyongyang over its nuclear weapons program.

In recent days, as the North has continued to test missiles in defiance of global pressure, President Donald Trump has started voicing doubt that Beijing is up to the task. His administration has taken a number of steps against China’s interests that have suggested its patience has run short.

Tillerson’s comments were the first public confirmation by the United States that the missile was indeed an ICBM, constituting a major technological advancement for the North and its most successful missile test yet.

The prime danger from the U.S. viewpoint is the prospect of North Korea pairing a nuclear warhead with an ICBM. The latest U.S. intelligence assessment is that the North probably does not yet have that capability — putting a small-enough nuclear warhead atop an ICBM.

Initial U.S. military assessments had been that it was an intermediate-range missile. NORAD, or the North American Aerospace Defense Command, said the missile did not pose a threat to North America.

Trump, in his initial response to the launch on Monday evening, urged China on Twitter to “put a heavy move on North Korea and end this nonsense once and for all!” But he also said it was “hard to believe” that South Korea and Japan, the two U.S. treaty allies most at risk from North Korea, would “put up with this much longer.”

The U.S. mission to the United Nations said that U.S. Ambassador Nikki Haley had requested that the Security Council meet urgently along with the U.N. envoys from Japan and South Korea. The 3 p.m. meeting today was to be held “in the open chamber,” rather than behind closed doors.

The launch was not wholly unexpected. Daniel Coats, director of national intelligence, testified to Congress in May that the U.S. anticipated an ICBM test before the end of this year.

The Pentagon has spent tens of billions of dollars developing a missile defense system tailored to the North Korean ambition of attaining the eventual capability to attack the U.S. with a nuclear-armed missile. On May 30 the Pentagon successfully shot down a mock warhead designed to replicate the North Korean threat.