HAMBURG, Germany -- President Trump assailed North Korea as a "problem and menace" Saturday as he met with Asian allies on the sidelines of an international summit to build consensus on next steps after the North's recent test-launch of an intercontinental ballistic missile (ICBM).

"Something has to be done about it," Mr. Trump said as he met with Chinese President Xi Jinping. "It may take longer than I'd like. It might take longer than you'd like, but there will be success in the end one way or the other."

In a separate meeting with Japanese Prime Minister Shinzo Abe, Mr. Trump said the two were tackling "the problem and menace of North Korea."

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Abe, speaking through a translator, noted that the security situation in the Asia Pacific region has 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 U.S. 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 extensive slate of meetings with Abe, Xi, British Prime Minister Theresa May and others came on the final day of the annual Group of 20 summit, which has been marked by violent demonstrations by anti-globalization activists.

North Korea has been a major topic of discussion, and the White House said earlier that the U.S., South Korea and Japan were pressing for additional measures against North Korea to demonstrate the "serious consequences" for its latest provocations.

The three nations have been calling for "early adoption" of a new U.N. 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 White House has tried to pressure Beijing to rein in the North, a major trading partner, to halt Kim Jong Un's development of nuclear weapons before they have the ability to threaten the U.S. homeland.

The administration wants China to fully enforce international sanctions intended to starve Pyongyang of revenue for its nuclear and missile programs. But Mr. Trump has been frustrated by the amount of progress.

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

Trade between China and North Korea grew almost 40% in the first quarter. So much for China working with us - but we had to give it a try! — Donald J. Trump (@realDonaldTrump) July 5, 2017

Mr. Trump officials said later that the president hadn't given up on the relationship.

Trade was also a key part of the discussions. The Mr. 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.

Meeting with May, the British leader, Mr. Trump pointed to their "special relationship," and said the two countries were working on a trade agreement.

May was the first foreign leader to visit Mr. Trump at the White House and he told her he would soon "be going to London" once details were worked out. Independent trade negotiations between the two countries are a possibility as Britain exits the European Union -- a move Mr. Trump has supported.

Earlier, Mr. Trump said Saturday he had a "tremendous meeting" with Russian President Vladimir Putin on Friday, his first comments on the high-profile talks with the Russian leader. Mr. Trump raised the issue of Russia's meddling in the 2016 elections and discussed plans for a cease-fire agreement in Syria.

U.S. Secretary of State Rex Tillerson said Mr. Trump and Putin had a "robust and lengthy" discussion about Russian election interference but Putin denied any involvement. His Russian counterpart, Foreign Minister Sergey Lavrov, said Mr. Trump had accepted Putin's assurances that Russia didn't meddle in the U.S. election -- a characterization that the U.S. disputed.

"I think the president is rightly focused on how do we move forward from something that may be an intractable disagreement at this point," said Tillerson, who took part in the meeting along with Lavrov.

Russian officials sought to address the conflicting accounts. Asked about the discrepancies on Saturday, Putin spokesman Dmitry Peskov joked, "Trust Lavrov. I don't work for Tillerson."

Mr. Trump also joined a women's entrepreneurial finance event, a project spearheaded by his daughter and senior adviser Ivanka Mr. Trump.

Ivanka Trump and the World Bank rolled out a new fund that aims to help female entrepreneurs access capital, financing and other support. World Bank President Jim Yong Kim said the Women Entrepreneurs Finance Initiative fund had so far raised $325 million from various governments.

Mr. Trump lauded his daughter's efforts to help female entrepreneurs, joking that "if she weren't my daughter, it would be so much easier for her."

Mr. Trump planned to return to Washington on Saturday evening after the conclusion of the annual G-20 meetings. He won't be stateside for long: The president is scheduled to return to Europe next week to attend Bastille Day celebrations in Paris.