As concerns grow over North Korea's military provocations, a range of experts are warning that for various reasons, the U.S. cannot count on China as a reliable partner in defusing the crisis on the Korean Peninsula.
Early Sunday, the U.S. military said it had conducted a successful test THAAD weapon system test over the Pacific Ocean, a response to Pyongyang's latest missile test. That came on the heels of South Korea announcing a new precision ballistic missile it claimed is capable of destroying North Korea's nuclear facilities and tunnel strongholds.
On Friday, The North Korean government test-fired a Hwasong-14 intercontinental ballistic missile into the Sea of Japan. That prompted a furious Twitter tirade from President Donald Trump, who berated China on its inability, or unwillingness, to control its ally.
For its part, China is concerned about the repercussions of North Korea's regime collapsing, including a civil war in an impoverished country with nuclear and chemical weapons. Beijing also is worried a fall of the regime could result in millions of refugees streaming across the border into China, observers say.
"I've been told by senior Chinese officials: 'Look we don't like the status quo but it's certainly a lot better than the alternative,'" said Harry Kazianis, director of defense studies at the Center for the National Interest, a Washington, D.C.-based public policy think tank founded by former President Richard Nixon.
Another reason the administration remains wary of negotiations is previous U.S. attempts at denuclearization have failed, even after substantial assistance to North Korea. In April, Secretary of State Rex Tillerson pointed out the U.S. had provided the North with about $1.3 billion in aid since 1995.
Those factors are playing out against a backdrop of a potential military conflict that grows more acute by the day. Experts now estimate the long-range missile can reach at least half of the continental United States. Yet Joel Wit, a senior fellow at the U.S.-Korea Institute at Johns Hopkins School of Advanced International Studies, told CNBC that all was not yet lost.
"I think the 'window of opportunity' is still open for dialogue," said Wit, a co-founder of Washington's 38 North think tank and a former State Department official.
He added that it's time for the Trump administration to sit down and hold "a serious security dialogue" with Pyongyang—and forget about taking the "dead-end" sanctions route.
In response to the Friday ICBM test-firing, South Korea and the U.S.military forces conducted joint ballistic missile exercises, according to South Korea's Yonhap news agency. There are about 28,500 U.S. troops stationed in South Korea and about 50,000 U.S. forces in Japan.
Additionally, South Korea's President Moon Jae-in on Saturday ordered the deployment of four more mobile launchers of the controversial Terminal High-Altitude Area Defense (THAAD) anti-missile system. China has protested the THAAD system, because it claims the missile shield's radar allows it to peer deep into China.
Seoul also warned North Korea it has a powerful new ballistic missile in its arsenal with precision-strike capability and features that allow it to be launched in seconds for lethal strikes.
The South Korean president's decision to expand the U.S.-supplied THAAD missile shield system is a departure from his earlier stance of holding back on further deployment of the system until environmental reviews were conducted. South Korea already has two THAAD units deployed about 135 miles outside Seoul.
In a written statement Friday, President Donald Trump called the test-firing of the ICBM "only the latest reckless and dangerous action by the North Korean regime. The United States will take all necessary steps to ensure the security of the American homeland and protect our allies in the region."
So far, economic sanctions pushed by the Trump administration haven't stopped the North Koreans from abandoning their nuclear weapons and ballistic missile programs. Trump was expected over the weekend to sign new sanctions that target not only North Korea, but also Iran and Russia.
In April, Trump held a summit with Chinese President Xi Jinping at his Mar-a-Lago estate in Florida. Trump asked Xi for help in putting pressure on North Korea to abandon its nuclear and missile programs.
Some experts suggest Trump misjudged exactly how far the Chinese president would go to help rein in North Korea. China is the North's long-time ally, and also its biggest trading partner.
The president is "not going to cut a deal with Xi," said Ed Turzanski, an international policy and national security expert at the Foreign Policy Research Institute. Turzanksi worked in the U.S. intelligence community during the Reagan administration.
According to Turzanski, leaders such as China's Xi and Russia's President Vladimir Putin "are not interested in forming personal relationships and cutting win-win deals, because in large part they still operate on a zero-sum game — you win, I lose," Turzanski explained.
"They are cold-blooded in calculating when it comes to national interests, and they are not going to do you any favors," he added.
Others suggest the Beijing is unlikely to provide much help on North Korea, and also harbors fears of their own about Pyongyang.
"Don't look for the Chinese to help us on North Korea," said Kazianis, at the Center for the National Interest. "If you look at it from the Chinese eyes, they are probably actually more scared of North Korea than we are."
Wit, the former U.S. diplomat, believes there's still a chance for the U.S. to get the upper hand but not through sanctions. He believes the U.S. can agree to scale back joint exercises with South Korea and still protect its ally.
Last month, North Korea's ambassador to India said the regime was "willing to talk" with the U.S. about freezing its nuclear and missile tests. That said, one of the conditions was the U.S. "completely stop" large-scale joint military exercises with South Korea, temporarily or permanently.
Yet after Pyongyang's brutal treatment of American student Otto Warmbier, some are opposed to any negotiations. Warmbier died days after release from the regime's custody.
At least three other Americans are known to still be in detention.
Bruce Klingner, senior research fellow for Northeast Asia at the Heritage Foundation's Asian Studies Center, opposes any negotiations at this time. He said South Korea has tried more than 200 agreements, not all nuclear, and those too failed to moderate the secretive regime's behavior.
Over a stretch of two decades, Klingner said there's been various multi-party talks with the North Koreans, which have largely gone nowhere.
"We need to avoid a premature return to negotiations," said Klingner, a former chief of the CIA's Korea branch.