In another menacing act of brinkmanship, President Donald Trump declared in a tweet yesterday that China had failed to force North Korea to accede to US demands, opening the door for unilateral US action, including military strikes. The tweet comes just ahead of top-level talks between US and Chinese officials due to take place in Washington today.

“While I greatly appreciate the efforts of President Xi [Jinping] & China to help with North Korea, it has not worked out. At least I know China tried!” Trump tweeted.

The Trump administration has put great pressure on Beijing to compel Pyongyang to abandon its nuclear and missile programs, but has indicated all along that time was limited. “North Korea is looking for trouble. If China decides to help, that would be great. If not, we will solve the problem without them! USA,” Trump tweeted in April.

The US president’s latest tweet is clearly aimed at placing additional pressure on Chinese officials—State Councillor Yang Jiechi and General Fang Fenghui—who will meet with US Secretary of State Rex Tillerson and Defence Secretary James Mattis in a US-China Diplomatic and Security Dialogue.

The US State Department has indicated that Washington intends to put North Korea at the top of the agenda, and to press China to agree to harsher sanctions, such as an oil embargo and bans on North Korean guest workers. Beijing, however, which has already helped impose harsh sanctions on North Korean mineral exports, is reluctant to make moves that could provoke a political crisis in Pyongyang—on China’s doorstep.

China’s ambassador in Washington, Cui Tiankai, told the Financial Times: “We should not make it [US-China dialogue] a platform where one side pushes a long list of demands on the other. It has to be a two-way street.” He said that China was “obviously important” in exerting pressure on North Korea, “but there is more the US should do.” Beijing has urged Washington to take steps towards reviving negotiations with Pyongyang.

Trump’s tweet that China’s efforts have “not worked out” is more than just a bargaining ploy at today’s talks. If Beijing refuses to agree to tougher sanctions, the danger of reckless US military action against Pyongyang rises. As a senior administration official told Reuters, the US has limited options to rein in North Korea without Chinese assistance.

Trump officials have already declared that the Obama administration’s policy of “strategic patience”—pressuring Pyongyang with increased sanctions—had failed. The possibility of a meeting with North Korean leader Kim Jong-un, which Trump suggested last month might be realizable under the right conditions, is highly unlikely. White House spokesman Sean Spicer declared yesterday, “clearly we’re moving further away, not closer to those conditions.”

In reality, the Trump administration, along with the American media, has seized on the death of Otto Warmbier to further demonise North Korea and create the conditions for war. Warmbier, a college student, was one of four American citizens convicted and jailed in North Korean prisons. He was flown home last week and died on Monday.

Trump joined the clamour in the media and political establishment for action over Warmbier’s death, declaring what happened “a total disgrace.” He branded the North Korean government “a brutal regime” and said that the death had deepened his determination to prevent other tragedies “at the hands of regimes that do not respect the rule of law or basic human decency.”

US Senator John McCain, chairman of the Senate armed services committee, bluntly stated that the Kim Jong-un regime had “murdered” Warmbier—even as doctors have yet to determine what caused the brain danger that led to the student’s death. McCain accused Pyongyang of “forced labour, mass starvation, systematic cruelty, torture and murder” and added that the US “cannot and should not tolerate the murder of its citizens by hostile powers.”

All the preparations for a US-led war on North Korea have been made. The Pentagon has stationed what Trump referred to as “an armada” off the Korean Peninsula—two aircraft carrier strike groups are in place and another is on its way, along with nuclear submarines—supplementing substantial American forces already stationed in Japan, South Korea and Guam.

Yesterday, two US B-1 strategic bombers flew over the Korean Peninsula in another warning to North Korea. The 10-hour flight from Guam also involved training missions with both Japanese and South Korean F-15 fighters. Pentagon spokesman Jeff Davis told the media: “We can launch and operate long-range bombers over the Korean Peninsula on very short notice.” He then ominously added: “And we hope not to have to do that.”

In another rather menacing signal, two US officials told CNN that American spy satellites had detected new activity at North Korea’s underground nuclear test site. The officials expressed concern that North Korea could detonate a nuclear test to coincide with the US-China dialogue taking place in Washington. Pyongyang has been publicly critical of Beijing’s willingness to agree to US demands for sanctions.

The CNN report also noted the very advanced character of the Pentagon’s plans for war against North Korea, stating: “Two senior US officials with direct knowledge also told CNN that military options for North Korea have recently been updated, and will be presented to President Donald Trump for a decision to act if there is a nuclear test.”

The devastating character of any new war on the Korean Peninsula was again underscored last week by US Defence Secretary James Mattis. He told a congressional committee that such a conflict would be “catastrophic” but that the US would ultimately prevail.

“It will be a war more serious in terms of human suffering than anything we have seen since 1953,” Mattis said, referring to the Korean War between 1950 and 1953 in which the casualties ran into the millions. “It will involve the massive shelling of an allies’ capital [Seoul], which is one of the most densely packed cities on Earth. It would be a war that fundamentally we don’t want. Our allies and us would win at great cost.”

However, it is also a war that the Trump administration is relentlessly edging towards, having repeatedly declared that “all options are on the table.” Unlike the Korean War of the 1950s, a new conflict would not remain confined to the Korean Peninsula but would draw other powers into a far wider catastrophe for humanity.