North Korea's latest test launch of an intercontinental ballistic missile marks a direct challenge to President Donald Trump, whose tough talk has yet to yield any change in Pyongyang's behavior as the regime continues its efforts to build a nuclear weapon capable of striking the mainland United States.

The missile - launched Tuesday in North Korea, late Monday in the United States - flew higher and remained in the air longer than previous attempts, enough to reach all of Alaska, experts said. They called it a major milestone for North Korea's weapons program.

The test comes just before Trump will see key Asian leaders and Russian President Vladimir Putin later this week. North Korea was already expected to be a main subject for meetings on the sidelines of the Group of 20 economic summit, but the test adds urgency to a widening U.S. campaign aimed at further isolating North Korea.

The day after the launch, the U.S. Army and the South Korean military conducted a missile exercise in response to "North Korea's destabilizing and unlawful actions," U.S. Pacific Command said in a statement. It was unclear how Pyongyang might react to the exercise, which launched missiles into South Korean territorial waters along the country's eastern coastline.

"Together with the Republic of Korea, we conducted a combined exercise to show our precision-fire capability," said Dana White, a Pentagon spokeswoman.

Trump responded to the North Korean missile test by applying rhetorical pressure on China, North Korea's ally and economic lifeline, and by mocking dictator Kim Jong Un on Twitter.

"North Korea has just launched another missile. Does this guy have anything better to do with his life?" Trump asked in a message very shortly after the launch.

"Hard to believe that South Korea and Japan will put up with this much longer," Trump continued. "Perhaps China will put a heavy move on North Korea and end this nonsense once and for all!"

The launch follows a string of recent actions by Pyongyang, including a salvo of missiles last month and three tests in May. Kim has now launched more missiles in one year than his father and predecessor in the family dynasty did in 17 years in power.

North Korea has also conducted five nuclear weapons tests since 2006, including two last year.

The number and variety of tests worry experts who see each step as part of a march toward a missile capable of striking America's West Coast.

The missile tests violate existing United Nations and other sanctions, which North Korea has found ways to evade. Although Trump and Secretary of State Rex Tillerson have declared that the "era of strategic patience" with North Korea is over, the new U.S. administration has not spelled out what that means.

Tillerson has said Washington might eventually negotiate with North Korea under the right circumstances, but he has suggested that possibility is remote. The United States will act alone if it must, he has warned, though he has not spelled out what exactly that would entail.

The Trump administration has recently leaned on China to rein in North Korea and curb illicit trade with the country, an international pariah largely cut off from the global financial system.

Given that Japan and South Korea are within range of existing North Korean missiles, Trump has also sought to unite leaders of both nations behind a strongly worded U.S. position that it will no longer tolerate the North's provocations. The Trump administration has asked other nations around the globe to sever or downgrade diplomatic ties with Pyongyang.

Leaders of China, South Korea and Japan will be at the G-20 meeting in Germany.

Japanese Prime Minister Shinzo Abe appeared to share Trump's frustration, if not his tone. In remarks to the news media, he vowed to work closely with the United States and South Korea, but called on China and Russia to do more.

"I'd like to strongly urge international society's cooperation on the North Korea issue and urge China's chairman, Xi Jinping, and Russia's President Putin to take more constructive measures," Abe said.

In a daily news conference, Geng Shuang, a spokesman for China's Foreign Ministry, condemned the test but countered that Beijing had "spared no effort" in its fight.

On Tuesday, Russia and China jointly proposed that North Korea put further nuclear and missile tests on hold while the United States and ally South Korea refrain from large-scale military exercises. Both Russia and China oppose North Korea's nuclear weapons program. Both also oppose the U.S. antimissile system being installed in South Korea.

Experts said the Trump administration does not have many choices for what to do next.

"Unfortunately, the Trump administration has few options other than robust economic pressure on China and North Korea," said Anthony Ruggiero, a specialist on the long-running diplomatic and military standoff at the Foundation for Defense of Democracies. "The U.S. wasted the last 10 years with a combination of negotiations that were destined to fail and strategic patience that failed from the start."

A new sanctions regime led by the United States would be the best response, Ruggiero said, because China and Russia would veto the most effective form of sanctions at the U.N. Security Council.

Last week, the Trump administration announced sanctions targeting a China-based bank accused of laundering money for the North Korean government and moved forward with an arms sale to Taiwan that Beijing opposes.

Trump followed up with a call Sunday to China's Xi, in which Trump "raised the growing threat posed by North Korea's nuclear and ballistic missile programs," according to the White House.

"Both leaders reaffirmed their commitment to a denuclearized Korean Peninsula," a White House statement said, while "President Trump reiterated his determination to seek more balanced trade relations with America's trading partners."

The trade reference was an implicit threat to reassert U.S. complaints about Chinese economic practices that Trump has largely set aside in recent months as he has sought to engage Xi, with whom he claims a strong relationship.

China has pledged cooperation with the United States over North Korea but has not fundamentally shifted away from a strategy that balances pressure on the Kim regime with keeping the regime afloat, said Chris Steinitz, a research scientist at the federally funded, nonprofit Center for Naval Analyses.

"It's kind of how China looks at everything. They have a very long view," Steinitz said. "They will wait, they will bide their time. They have a lot of priorities."

In the meantime, Steinitz said, North Korea will continue to test missiles.

The U.S. military said the Hwasong-14 was in the air for 37 minutes, a duration that signals a significant improvement over previous tests. In a special announcement on state television, North Korea said the missile flew about 579 miles, reaching an altitude of 1,741 miles.

The launch was made from a site in North Korea's North Pyongan province, and the missile flew more than 500 miles before landing in waters off Japan's coast, U.S., South Korean and Japanese officials said.

As with other recent launches, the missile appears to have been fired at a very steep trajectory in an effort to avoid flying over neighbors.

Multiple independent analyses of the test showed that the missile flew at a high-altitude trajectory, soaring to about 1,700 miles before landing in the Pacific off the Japanese coast, about 580 miles from its launch point.

The Pentagon and the State Department confirmed late Tuesday that North Korea had launched an ICBM.

"The United States strongly condemns North Korea's launch of an intercontinental ballistic missile," Tillerson said in a statement. "Testing an ICBM represents a new escalation of the threat to the United States, our allies and partners, the region, and the world."

Tillerson added that the United States intends to bring the issue before the U.N. Security Council to hold North Korea accountable. On Tuesday, the U.S. ambassador to the United Nations, Nikki Haley, announced that she and her counterparts in Japan and South Korea had requested an emergency Security Council meeting, set for Wednesday afternoon.