By Jeff Mason and Roberta Rampton
WARSAW (Reuters) - U.S. President Donald Trump vowed on Thursday to confront North Korea "very strongly" following its latest missile test and urged nations to show Pyongyang that there would be consequences for its weapons program.
North Korea on Tuesday test-launched an intercontinental ballistic missile that some experts believe has the range to reach the U.S. states of Alaska and Hawaii and perhaps the U.S. Pacific Northwest. North Korea said it could carry a large nuclear warhead.
Speaking at a news conference with Polish President Andrzej Duda, Trump said Korea was "a threat, and we will confront it very strongly".
He said the United States was considering "severe things" for North Korea, but that he would not draw a "red line" of the kind that his Democratic predecessor, Barack Obama, had drawn but not enforced, on the use of chemical weapons in Syria.
"... they are behaving in a very, very dangerous manner and something will have to be done."
The issue presents Trump, who took office in January, with perhaps his biggest foreign policy challenge. It has put pressure on his relationship with China's President Xi Jinping, whom Trump had pressed without success to rein in Pyongyang.
The United States said on Wednesday that it was ready to use force if necessary to stop North Korea's nuclear missile program, prompting China on Thursday to call for all sides to remain calm and exercise restraint.
Meeting in Germany ahead of a G20 summit, Xi told South Korean President Moon Jae-in that China supported the new South Korean government's efforts to restart dialogue and contacts with the North, and that all sides should strictly abide by U.N. Security Council resolutions, the state news agency Xinhua said.
South Korean presidential spokesman Park Su-hyun gave a more robust account of the conversation, telling reporters that the two men had agreed that North Korea's missile test was "unforgivable", and had discussed stepping up pressure and sanctions.
Trump, who was heading for Hamburg later on Thursday to attend the summit, is due to meet with Xi there.
His frustration that Beijing has not done more to clamp down on North Korea prompted him to tweet on Wednesday: "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!"
Trump did not mention China specifically in his remarks in Poland, but his message that other countries needed to do more was clearly meant for Beijing.
"President Duda and I call on all nations to confront this global threat and publicly demonstrate to North Korea that there are consequences for their very, very bad behavior," he said.
U.S. Ambassador to the United Nations Nikki Haley told a meeting of the U.N. Security Council on Wednesday that the United States would propose new U.N. sanctions on North Korea in coming days, and that if Russia and China did not support the move, then "we will go our own path".
Some diplomats say Beijing has not been fully enforcing existing international sanctions on its neighbor and has resisted tougher measures, such as an oil embargo, bans on the North Korean airline and guest workers, and measures against Chinese banks and other firms doing business with the North.
U.S. officials have said the United States might specifically seek to sanction more Chinese companies that do business with North Korea, especially banks.
Chinese Vice Finance Minister Zhu Guangyao said in Hamburg on Thursday that Beijing would implement all sanctions imposed on North Korea as a result of its missile tests, but warned Washington not to use them as an excuse to impose sanctions against Chinese financial institutions.
(additional reporting by Marcin Goettig)