Haley's pointed remarks at the U.N. came in reaction to a successful ballistic-missile test by Pyongyang.
The top U.S. diplomat to the United Nations blasted Russia and China on Wednesday for "holding the hand" of North Korean leader Kim Jong Un, as the Trump administration struggled to respond to Pyongyang's latest ballistic-missile test.
U.N. Ambassador Nikki Haley chided Moscow and Beijing over their opposition to a Security Council resolution condemning North Korea and imposing greater economic sanctions for what she called its "sharp military escalation."
She also said Pyongyang was "quickly closing off the possibility of a diplomatic solution" and suggested the United States would continue to consider military action if necessary.
"One of our capabilities lies with our considerable military forces," Haley said during a Security Council meeting in New York. "We will use them if we must, but we prefer not to have to go in that direction."
Haley's pointed speech marked the latest effort by the Trump administration to rally allies and rivals around a common agenda to blunt North Korea's progress, days after Kim's regime tested an intercontinental ballistic missile with a range that experts said would put it within reach of Alaska.
But her remarks also illustrated the limits of the White House's options and lacked specifics about what concrete steps the administration is considering. The missile test marks a new level of advancement in Kim's pursuit of a nuclear weapon that could strike the continental United States. Analysts said a military confrontation could escalate quickly into a mass-casualty war on the Korean Peninsula and Japan, where the United States has stationed tens of thousands of troops.
The standoff cast a shadow as President Donald Trump prepared for his first meeting with Russian President Vladimir Putin and his second with Chinese President Xi Jinping on the sidelines of the Group of 20 summit, which opens Friday in Hamburg. Trump also will meet with Japanese Prime Minister Shinzo Abe and the heads of U.S. allies Britain and Germany.
"We've been pretty consistent that we are never going to broadcast next steps," deputy White House press secretary Sarah Huckabee Sanders told reporters aboard Air Force One as the president traveled to a short stop in Warsaw on Wednesday.
Before leaving Washington, Trump revealed more frustration with Xi, whom he has personally lobbied to enact sanctions on Chinese banks that do business with North Korean companies. The U.S. Treasury Department announced last week that it would block the Bank of Dandong, along the border region between China and North Korea, from accessing U.S. markets. Officials said was the first of potentially greater sanctions by the United States.
On Twitter, Trump wrote: "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!"
Chinese data released in April showed China's trade with the North grew 37.4 percent during the first three months of the year compared with the same period in 2016. China said then that overall trade grew even as it complied with U.N. sanctions and stopped buying North Korean coal.
Russian and Chinese diplomats used the U.N. Security Council meeting to push their joint proposal for a suspension of North Korean nuclear and missile testing in exchange for a suspension of U.S. and South Korean military exercises. Both countries also condemned the U.S. antimissile system being deployed in South Korea and called for it to be removed.
Early Wednesday in Asia, U.S. and South Korean forces fired missiles, conducting joint military exercises that the U.S. Pacific Command cast as a show of "ironclad" resolve.
Daniel Pinkston, a lecturer in international relations at Troy University in Seoul, said he saw no chance Washington and Seoul would agree to halt joint exercises, calling it "a non-starter."
During the U.N. meeting, a Russian official questioned whether North Korea's missile was an ICBM, suggesting it was an intermediate-range weapon.
That prompted Haley to request a second turn at the microphone, during which she said: "If you see this as a threat, if you see this for what it is, which is North Korea showing its muscle, then you need to stand strong. If you chose not to, we will go our own path."
Danny Russel, who served as senior Asia director at the National Security Council under President Barack Obama, said Trump has a "rare blue moon" opportunity this week to meet with and rally the major players - China and Russia on one side and Japan and South Korea on the other - toward some sort of unified display of condemnation of North Korea.
"What the administration needs to do is get China and Russia around an approach, even if it is not as testosterone-rich and muscular as the U.S. would like, so that the basic geometry is five on one, not three on three," said Russel, now a diplomat in residence at the Asia Society in New York. "There is no formula, no path forward, other than war, that isn't built on some degree of common cause between Washington and Beijing."
Victor Cha, who served as senior Asia director at the NSC under President George W. Bush, said the U.S. sanctions on the Dandong bank were "a shot across the bow at the Chinese that what is happening is not working for us. It arguably gives [Trump] a stronger position going in" to the meeting with Xi.
South Korean authorities described North Korea's test as a two-stage missile with a range of about 4,300 to 5,000 miles - enough to reach Alaska and other parts of North America.
South Korean Defense Minister Han Min-koo said there is high probability that Pyongyang will stage another nuclear test and noted gains in its efforts to miniaturize a warhead - steps toward developing nuclear-tipped weapons capable of hitting the mainland United States.
Pyongyang's test appeared to catch the United States by surprise. The Pentagon initially mislabeled the activity as a test of an intermediate-range missile before reclassifying it Wednesday as an ICBM with a range of at least 5,500 kilometers.
Navy Capt. Jeff Davis, a Pentagon spokesman, said that the missile "is not one we have seen before" and that it was launched from a site - the Panghyon airfield about 90 miles north of Pyongyang - that has not been used to test missiles before.
He emphasized that North Korea still has a number of steps to meet before a threat to North America is imminent, noting that Pyongyang has not yet demonstrated the ability to mount a nuclear warhead on a ICBM or show the lateral range necessary.
North Korea successfully test fired an intercontinental ballistic missile July 3. The missile was launched into a steep arc sending it more than 1,700 vertical miles up before beginning its reentry into Earth's atmosphere. (Jason Aldag, Joby Warrick, William Neff / The Washington Post)
Rauhala reported from Beijing. Anne Gearan and Dan Lamothe in Washington contributed to this report.
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