AP Photo/Lee Jin-man
US Vice President Mike Pence speaks to the media at the border village of Panmunjom which has separated the two Koreas since the Korean War, South Korea, Monday, April 17, 2017.
Vice President Mike Pence visited the demilitarized zone between North and South Korea on Monday, stressing that the US's strategic patience with North Korea was over, and that the US is considering the use of military force.North Korea's Vice-Foreign Minister Han Song-ryol shot back just hours later, saying if "the US is planning a military attack against us, we will react with a nuclear pre-emptive strike by our own style and method," and threatened "all-out war" in response to any US action.
On a call with reporters, the State Department told Business Insider there would be a ""significant international response" if North Korea carried out further nuclear testing.
The exchange, while troubling, has become familiar since North Korea's nuclear and missile testing programs accelerated and President Donald Trump has taken a harder line against the Kim regime.
While experts have said with near unanimity that a US military strike on North Korea would present grave danger or an outright nuclear catastrophe, another option frequently brandished by Trump has been leveraging the US's trade relationship with China, North Korea's biggest backer, to act.
But the US may be overestimating China's pull with Kim Jong Un, according to Jenny Town, the assistant director of the US-Korea Institute and a managing editor at 38 North, a website that brings together experts on North Korea.
"China and North Korea relations have not been great to begin with," Town told Business Insider. Unlike Kim's father and predecessor, Kim Jong Un has never been to China to meet with Chinese President Xi Jinping, Town noted.
Town said that, in the past, Beijing could have reined in North Korea. But Kim Jong Un has engaged in killing off senior officials with ties to China, thereby insulating himself. Reuters recently reported that the latest calls from Chinese diplomats to North Korea had gone unanswered.
AP Photo/Wong Maye-E
North Korean leader Kim Jong Un arrives for the official opening of the Ryomyong residential area, Thursday, April 13, 2017, in Pyongyang, North Korea.
"In China they're very frustrated," said Town. "North Korea has progressed further than what they're willing to accept" and the provocations coming out of North Korea make the relationship very difficult for the Chinese to manage.
Though White House spokesman Sean Spicer said on Monday that the burgeoning relationship between Xi and Trump has paid off, Town said that the US calling for China to simply shut off the Kim regime from trade is "a naive oversimplistic view of the situation."
Town said it would be a mistake to assume that North Korea would react to China shutting off trade by crawling back to the table. North Korea could potentially find other trade partners, and even retaliate against China.
"Floods of refugees, some kinds of military coup.... the Chinese aren't ready yet to take those risks," said Town.
But while Trump tries to force China's hand against North Korea, where their leverage may be been overestimated, he refuses to give an inch on the US's end.
AP
This Sept. 2, 2014 photo shows an entrance in Sinuiju, from North Korea towards China to the "Korea China Friendship Bridge" - the old bridge connecting the two socialist states over the Yalu River.
The US lately has completely dismissed unconditional talks with North Korea, instead seeming to float military options with increasing urgency. The US currently has an aircraft carrier off North Korea's coast and has deployed additional missile defenses to South Korea.
"They need to have some level of exploratory talks," Town said of the Trump administration, noting that they could be undergoing back channel or secret talks. "Until you get to the table you don't even know what's on the table."
The testy back and forth on Monday between Pence and Han, and the decades of threats flying back and forth suggests that a new approach may be warranted.
"Going straight towards threatening military options is just adding fuel to the fire," said Towns.