Wrapping up his second European tour as president, Donald Trump and the leaders of China and Japan searched for consensus on Saturday on how to counter what the president called the “menace” of North Korea after its test-launch of an intercontinental ballistic missile (ICBM).

“Something has to be done about it,” Trump said as he met with the Chinese president, Xi Jinping. In a separate meeting with the Japanese prime minister, Shinzo Abe, Trump said the two were tackling “the problem and menace of North Korea”.

The White House has tried to pressure Beijing to rein in North Korea, a major trading partner, to halt Kim Jong-un’s development of nuclear weapons before they have the ability to threaten the US homeland. Trump has voiced his frustration in recent days that China hasn’t done more, suggesting he may be moving on.

But during his meeting, Trump told Xi: “I appreciate the things that you have done relative to the very substantial problem that we all face in North Korea.”

Trump’s extensive slate of meetings with Abe, Xi and the British prime minister, Theresa May, among others, came on the final day of the annual G20 summit, which has been marked by violent demonstrations by anti-globalization activists. Trump also had a brief, unscheduled meeting with Turkey’s president, Recep Tayyip Erdoğan, about the situation in Syria.

Abe, speaking through a translator, noted that the security situation in the Asia Pacific region had become “increasingly severe” due to North Korea’s push to develop its ballistic missile and nuclear program. Abe said he wanted to “demonstrate the robust partnership as well as the bonds” between Japan and the US on the issue.

North Korea’s successful test launch of an ICBM was a major milestone in its long-term effort to build a missile that could carry a nuclear warhead to attack the United States.

The issue was a frequent topic of discussion at the summit, and the White House said earlier that the US, South Korea and Japan were pressing for additional measures against North Korea to demonstrate the “serious consequences” of its latest provocations.

The three countries have been calling for “early adoption” of a new UN security council resolution and additional sanctions to demonstrate to Pyongyang the consequences of its actions.

Bringing China on board is a key part of the plan. The administration wants China to fully enforce international sanctions intended to starve Pyongyang of revenue for its nuclear and missile programs. But Trump has been dissatisfied with China’s response.

Earlier in the week, he vented on Twitter that trade between China and North Korea had grown nearly 40% at the start of 2017. “So much for China working with us – but we had to give it a try!”

US officials said later that the president hadn’t given up on the relationship.

Trade was also a key part of the discussions. The Trump administration is investigating the possibility of putting new barriers on steel imports based on national security considerations, a move that could target China, which has flooded international markets with cheap steel exports.

“Many things have happened that have led to trade imbalances and we’re going to turn that around,” Trump said during the meeting with Xi. Trump said he wanted a new arrangement that is “equitable” and “reciprocal”.

