The United States pledged Wednesday to step up sanctions to force North Korea to resume dialogue over its nuclear program, but said it was not looking to bring Kim Jong-Un's regime to its knees.
After briefing senators at the White House, top US officials said President Donald Trump also aimed to pursue diplomatic measures with allies and regional partners.
"We are engaging responsible members of the international community to increase pressure on (North Korea) in order to convince the regime to deescalate and return to the path of dialogue," read a statement from Pentagon chief Jim Mattis, Secretary of State Rex Tillerson and Director of National Intelligence Dan Coats.
Earlier, Admiral Harry Harris, who heads the Pacific Command, welcomed recent moves by Beijing to defuse soaring tensions between Pyongyang and Washington, and suggested a non-military solution remained the preferred outcome.
"It's critical that we're guided by a strong sense of resolve, both privately and publicly, both diplomatically and militarily," Harris said in Washington.
"All options are on the table. We want to bring Kim Jong-Un to his senses, not to his knees."
During a White House luncheon with UN Security Council ambassadors Monday, Trump "was very clear that he will be the president who will deal with" North Korea and that military action remains an option, a senior diplomat said.
National security adviser H.R. McMaster told the 15 ambassadors that "there would be a military solution even if they don't want to do it," the diplomat said.
The message was "ideally we do this peacefully and politically, which means through China. But if that doesn't work, there is another plan, which is through the United States," said the diplomat, who asked not to be named.
- Missile-defense system -
Separately, a senior administration official told AFP that the United States is considering adding North Korea to its list of countries that are designated as "state sponsors of terrorism."
US troops in South Korea began on Wednesday deploying a contentious anti-missile system in South Korea that has infuriated China.
The Terminal High Altitude Area Defense (THAAD) system is being set up on a former golf course in the southern county of Seongju, and its arrival was met by hundreds of protesters, some of whom clashed with police.
Harris said the THAAD system "will be operational in the coming days."
China fears THAAD will weaken its own ballistic capabilities and says it upsets the regional security balance.
Harris also said the Pentagon should weigh whether to install missile interceptors on Hawaii, which could be one of the first parts of the United States in range of an improved North Korean missile, in addition to existing interceptors in California and Alaska.
- 'Rain of fire' -
Pentagon officials have stressed to Trump that there are no easy options for military intervention in North Korea.
Senator Tammy Duckworth, a former US military helicopter pilot who lost both legs in combat in Iraq, was dismissive of what she and colleagues heard at the White House briefing on North Korea.
"I could've gotten all that information by reading a newspaper," she told CNN. "It felt more like a dog and pony show to me than anything else."
Washington has deployed an aircraft carrier strike group to the peninsula amid signs the North could be preparing for a sixth nuclear test.
The deployment drew widespread derision after it emerged that instead of steaming toward the peninsula, the ships actually headed in the opposite direction for a few days to train with the Australian navy.
Harris said the USS Carl Vinson strike group was now in the Philippine Sea just east of Okinawa, "in striking range and power projection range of North Korea if called upon to do that."
Congressman Mac Thornberry, who heads the House Armed Services Committee, said there is "tremendous confidence" among administration officials on dealing with North Korea.
In Pyongyang's latest display of its military capabilities, Kim oversaw the country's largest-ever firing drill to mark the founding anniversary of its military, state-run media said Wednesday.
Seoul held a large annual drill of its own, involving some 100 artillery pieces, 90 armored vehicles and 50 aircraft, as well as 2,000 South Korean and US troops, the defense ministry said.