North Korean leader Kim Jong Un watches the launch of the Hwansong-15 missile, which is capable of reaching all parts of the United States, on Nov. 29, 2017. (Kcna Via Kns/AFP/Getty Images)

Pyongyang's launch of a new, long-range missile this week deepens a chief foreign policy dilemma for the Trump administration, putting the threat of a North Korean nuclear strike closer than ever before without revealing appealing solutions for American policymakers.

The debut of the intercontinental Hwasong-15 missile, which analysts said may for the first time put the U.S. capital within reach of a North Korean strike, was hailed by Pyongyang as a milestone in leader Kim Jong Un's quest to prove his country's nuclear strike capabilities.

While some of the launch's technical aspects remain unclear, including the missile payload and its precise range, the latest of more than 20 missile tests this year underscores Pyongyang's defiance in the face of intensifying U.S. military and economic pressure.

The new evidence of the Kim regime's growing military might may alter the thinking of senior American officials, who have yet to see a campaign of economic pressure bear fruit. That in turn could create an opening for diplomacy — or increase the risk of military confrontation, experts said.

"It changes the perception of time that policymakers have to come up with a solution," said Patrick Cronin, a senior adviser at the Center for a New American Security. "In a crisis, it makes people ask themselves, 'Should we take more risks?' "

President Trump on Wednesday vowed to tighten sanctions on Pyongyang, promising the North Korean threat would be "handled" in a way his predecessors had failed to do.

Speaking at a campaign-style rally in Missouri, Trump called the North Korean leader "Little Rocket Man" and a "sick puppy."

But options for immediate changes to his North Korea strategy are scant, with the isolated nation's economy already under heavy sanctions and U.S. military action constrained by regional allies' fears of punishing retaliation.

Already over the past year, the Pentagon has positioned new assets around North Korea and conducted repeated shows of force.

While Defense Secretary Jim Mattis and other senior defense leaders have stressed the U.S. military's readiness to use overwhelming force against North Korea, they have also counseled restraint when considering a conflict that would require a ground invasion and probably claim thousands, if not millions, of lives.

One area where the increasingly urgent threat to the U.S. mainland may result in new military activity is in enhanced U.S. missile defenses.

Already this fall, in a sign of growing congressional concern, lawmakers approved a substantial increase in missile defense funding. The Pentagon is also adding new ground-based interceptors designed to keep the United States safe from missiles fired from East Asia.

"We've seen this train coming for the last 20 years, but now this train is accelerating," said Tom Karako, a senior fellow at the Center for Strategic and International Studies. "What you're going to see is that missile defense is no longer an ideological issue."

National security experts also expect increased investment in efforts to disrupt missile launches before they occur, potentially using cyber means.

Less clear is whether the latest demonstration of North Korean power can open new diplomatic avenues.

In a statement following Tuesday's launch, Secretary of State Rex Tillerson said that "diplomatic options remain viable and open, for now."

Some experts suggest that an opportunity might occur early next spring, when South Korea hosts the Winter Olympics and Paralympics. The games, scheduled for February and March, are expected to coincide with annual military exercises that Seoul conducts with the United States.

If the United States were to delay those exercises, which North Korea has repeatedly condemned, timed with an event symbolizing international athletic cooperation, it could set the stage for dialogue, Cronin said.

But U.S. demands that Pyongyang agree to ending its nuclear program before the start of talks may scuttle diplomacy before it gets going.

"It's hard to see where this ends, especially when the U.S. policy these days is just focused on continuing pressure and waiting [for North Korea] to behave differently before getting back to negotiations," said Jenny Town, assistant director of the US-Korea Institute at Johns Hopkins School of Advanced International Studies.

Further complicating U.S. officials' attempt to foster a peaceful way out is Trump himself, who has publicly questioned Tillerson's diplomatic efforts and suggested that force may be the only solution.

His comments have not only unnerved Asian allies, but they may also have deepened North Korea's skepticism about U.S. overtures.

Senior officials in Pyongyang "have fully embraced brinkmanship to ensure their survival," said Christopher Steinitz, an analyst of North Korean leadership at CNA, a nonprofit research organization. "It's very high-stakes, but they see it as less risky than the other option, which is trust."

The effect of Trump's unpredictability is compounded by Kim's willingness to test U.S. strategic patience, as he brandishes his growing missile and nuclear arsenal. The combination, national security experts warn, increases the risk of disastrous miscalculation.

"This is where Trump becomes a factor," Cronin said. "The president wants a more decisive response than the mainstream military elite in our country, and that could be triggered by a [North Korean] provocation that's a bit too provocative."

Carol Morello and Anne Gearan contributed to this report.