Senior U.S. and Chinese officials began a series of meetings in Washington Wednesday, seeking to tackle the escalating North Korean threat. It is unclear if President Trump will attend any of the discussions, but he has already undermined the talks, telling Beijing its efforts to curb Pyongyang’s nuclear weapons development were just not good enough.

The first diplomatic and security conference, which replaces the strategic economic dialogue that was established under President George W. Bush and continued under President Barack Obama, will be co-chaired by Chinese State Councillor Yang Jiechi, U.S. Secretary of State Rex Tillerson and Defense Secretary James Mattis. General Fang Fenghui, a member of China’s Central Military Commission, will also take part.

Even if he skips the talks, Trump ensured that his presence will still be felt by the delegates by tweeting Tuesday that while he appreciated China’s efforts in relation to North Korea, it “has not worked out.”

China hit back Wednesday morning, with Foreign Ministry spokesman Geng Shuang telling reporters that Beijing’s efforts on North Korea were“indispensable,” and added the country had “played an important and constructive role” in seeking peace on the Korean peninsula.

It is unclear if anyone involved in the meeting was aware of what Trump was going to say on the eve of the talks, but his comments were likely — in part at least — prompted by the death of American student Otto Warmbier Monday, who was released by North Korea after 17 months in detention for stealing a propaganda poster. Warmbier was flown back to the U.S. in a coma, and his parents say he was tortured.

Wednesday’s meeting is the first of four agreed to when Trump met China’s President Xi Jinping in April at his Mar-a-Lago residence, after which it appeared the U.S. and China were on the same page when it came to stopping North Korea’s rapid development of nuclear weapons.

But some experts believe that no matter what China did since the April summit, it was never going to be enough. “There was never anyone who seriously understood the North Korea issue who ever thought that the Chinese were going to do enough to satisfy Donald Trump,” China analyst Bill Bishop told VICE News.

The problem is that the strategic goals of the U.S. and China do not overlap in any meaningful way when it comes to North Korea. While China certainly wants to see a North Korea without nuclear weapons, it is “much more interested in maintaining the status quo and stability in the region,” Bishop said.

“It is not illogical to apply pressure on China, because China has leverage that no one else has, [but] are the few months since April sufficient for China to have applied pressure to transform what is a pretty entrenched, intractable problem?” James Hannah, assistant head of the Asia programme at Chatham House told VICE News.

A report on Wednesday suggested North Korea’s ambassador to India said Pyongyang is willing to talk about freezing its nuclear and missile tests if its demands are met, in an apparent bid to open a dialogue with the U.S. However, one of those demands is the cancelling of joint military exercises between the U.S. and South Korea, something which is unlikely to happen.

While Washington is clearly worried about the threat North Korea’s rapidly advancing nuclear weapons program poses, Beijing is concerned that an all-out war with North Korea could lead to much bigger problems. “China is fearful of the collapse of the North Korean regime for a range of reasons, including refugees and the economic implications for itself, but also it doesn’t want a Korean peninsula that is unified under U.S. leadership,” Hannah said.

During his presidential campaign and in office, Trump has invested heavily, rhetorically at least, on resetting U.S. China relations and changing the narrative with regards to North Korea. However, despite the high-profile summit in April, and Trump’s public praise of China and Xi in particular, there have always been signs that Trump was ready to cut China out of his plans and go it alone when it came to North Korea.

At a briefing earlier this week ahead of the dialogue, Susan Thornton, acting assistant secretary of state for East Asian and Pacific affairs, said the North Korean nuclear issue was going to be top of the agenda at Wednesday’s summit, but reiterated the U.S. would impose sanctions on Chinese companies or individuals it believes to have economic and financial links to North Korea’s missile and nuclear programs.

While China claims it is pulling its weight when it comes to North Korea — cutting back on trade, imposing UN sanctions, attempting to open dialogue with Pyongyang — China watchers are unsure about exactly how much pressure it has actually applied since April. Either way, it appears the U.S. — or perhaps just the president — has decided that time is up and harsher measures are required.

If the U.S. does want to ramp up its efforts to clamp down on Pyongyang’s actions, then a likely target would be Chinese banks which trade with North Korea — a approach also taken with Iranian banks during U.S. attempts to limit Iran’s nuclear program.