UNITED NATIONS/SEOUL - The United States warned the North Korean leadership that it would be "utterly destroyed" if war were to break out, after Pyongyang test fired its most advanced intercontinental ballistic missile, putting the US mainland within range.The Trump administration has repeatedly said all options were on the table in dealing with North Korea's ballistic and nuclear weapons program, including military ones, but that it still prefers a diplomatic option.Still, speaking at an emergency UN Security Council meeting, US ambassador Nikki Haley warned:"We have never sought war with North Korea, and still today we do not seek it. If war does come, it will be because of continued acts of aggression like we witnessed yesterday ... And if war comes, make no mistake, the North Korean regime will be utterly destroyed."Haley said the United States has asked China to cut off oil supply to North Korea, a drastic step that Beijing - the North's sole major trading partner - has so far refrained from doing. Trump spoke with Chinese President Xi Jinping earlier on Wednesday and said more sanctions on Pyongyang would be enforced."Just spoke to President Xi Jinping of China concerning the provocative actions of North Korea. Additional major sanctions will be imposed on North Korea today. This situation will be handled!" Trump wrote on Twitter.Previous US administrations have failed to stop North Korea from developing nuclear weapons and a sophisticated missile program. Trump has also struggled to contain Pyongyang since he came to office in January.Urging China to use its leverage on Pyongyang and promising more sanctions against North Korea are two strategies that have borne little fruit so far.In a speech in Missouri about taxes, Trump, who has traded insults with the North in the past, referred to Kim with a derisive nickname. "Little Rocket Man. He is a sick puppy," Trump said.The latest missile was fired a week after Trump put North Korea back on a US list of countries it says support terrorism, allowing it to impose more sanctions.United Nations political affairs chief Jeffrey Feltman met with North Korea's Ambassador Ja Song Nam on Wednesday to tell him Pyongyang must "desist from taking any further destabilizing steps" after the country launched another ballistic missile.French President Emmanuel Macron said on Wednesday he was counting on UN Security Council members China and Russia to step up sanctions on North Korea."I am counting a lot in particular on China and Russia in order to take the most difficult and effective sanctions," Macron told France 24 television.North Korea, which conducted its sixth and largest nuclear bomb test in September, has tested dozens of ballistic missiles under Kim's leadership in defiance of international sanctions.North Korea said the new missile soared to an altitude of about 4,475 km (2,780 miles) - more than 10 times the height of the International Space Station - and flew 950 km (590 miles) during its 53-minute flight.It flew higher and longer than any North Korean missile before, landing in the sea near Japan. Experts said the new "Hwasong-15" missile theoretically gave North Korea the ability to hit the United States, including the East Coast, although it was not clear whether it could carry a nuclear weapon.North Korean state media said the missile was launched from a newly developed vehicle and that the warhead could withstand the pressure of re-entering the atmosphere, which if confirmed would be an important technical advance.Kim personally guided the test and said the new launcher was "impeccable," state media said. He described the new vehicle as a "breakthrough."North Korea also described itself as a "responsible nuclear power," saying its strategic weapons were developed to defend itself from "the US imperialists' nuclear blackmail policy and nuclear threat."Many nuclear experts say the North has yet to prove it has mastered all technical hurdles, including the ability to deliver a heavy nuclear warhead reliably atop an ICBM, but it was likely that it soon would.'THREATEN EVERYWHERE'US, Japanese and South Korean officials all agreed the missile, which landed within Japan's exclusive economic zone, was likely an ICBM."It went higher, frankly, than any previous shot they’ve taken, a research and development effort on their part to continue building ballistic missiles that can threaten everywhere in the world, basically," US Defense Secretary Jim Mattis told reporters at the White House.An international meeting in Canada in January is designed to produce "better ideas" to ease tensions over Pyongyang's nuclear and ballistic missile tests, Canadian officials said on Wednesday, although North Korea itself will not be invited.US Secretary of State Rex Tillerson said on Wednesday the United States has "a long list of additional potential sanctions, some of which involve potential financial institutions, and the Treasury Department will be announcing those when they’re ready to roll those out."US EAST COAST IN RANGE?The new Hwasong-15, named after the planet Mars, was a more advanced version of an ICBM tested twice in July, North Korea said. It was designed to carry a "super-large heavy warhead."Based on its trajectory and distance, the missile would have a range of more than 13,000 km (8,100 miles) - more than enough to reach Washington D.C. and the rest of the United States, the US-based Union of Concerned Scientists said.However, it was unclear how heavy a payload the missile was carrying, and it was uncertain if it could carry a large nuclear warhead that far, the nonprofit science advocacy group added.In just three months' time, South Korea hosts the Winter Olympics at a resort just 80 km (50 miles) from the heavily fortified border with North Korea.Pyongyang has said its weapons programs are a necessary defense against US plans to invade. The United States, which has 28,500 troops in South Korea as a legacy of the 1950-53 Korean War, denies any such intention.