Secretary of State Rex Tillerson said Friday that North Korea's growing nuclear capabilities are a direct threat to the United States, and Washington "will use all necessary measures" to defend itself against such aggression.
"In the face of such a threat, inaction is unacceptable for any nation," Tillerson said.
"We have been clear that all options remain on the table in the defense of our nation," the secretary told a packed chamber of the U.N. Security Council in New York. "But we do not seek, nor do we want, war with North Korea," he said.
Tillerson spoke at a meeting on North Korea's proliferation convened by Japan, which holds the rotating Security Council presidency this month.
"The United States will use all necessary measures to defend itself against North Korean aggression, but our hope remains that diplomacy will produce a resolution," Tillerson added.
He repeated his openness to talks with the North Koreans, but added the caveat that Pyongyang "must earn its way back to the table."
"The pressure campaign must and will continue until denuclearization is achieved," Tillerson said. "We will, in the meantime, keep our channels of communication open."
Said Japan's foreign minister, Taro Kono, who chaired the meeting, "A peaceful solution is desirable, however, it's North Korea that has consistently rejected such a solution."
Kono called on the international community to maximize pressure on Pyongyang to change course, and announced that Japan had just imposed asset freezes on 19 additional North Korean entities.
"In 2017, the DPRK conducted activities related to its nuclear and ballistic missile programs at an alarming and accelerated pace," U.N. Secretary General Antonio Guterres told council members. "Its actions show blatant disregard of the will and resolutions of the Security Council and undermines the international norm against nuclear testing," he said.
On September 3, Pyongyang carried out its sixth nuclear test, setting off an underground explosion that registered a 6.1 on the seismic scale.
"The DPRK remains the only country to continue to break the norm against nuclear testing," Guterres noted, using the abbreviation for North Korea's formal name.
Throughout the year, the regime has also conducted 20 ballistic missile launches, including the first tests of two intercontinental ballistic missiles (ICBMs), as well as new medium- and intermediate-range ballistic missiles.
International nuclear watchdog agency the IAEA has been unable to gain access to North Korea to verify the status of its nuclear program. It uses satellite imagery to help monitor developments.
The U.N. chief called on North Korea to comply with all Security Council resolutions and to allow space for the resumption of dialogue. In a rare appearance at the council, North Korea's U.N. ambassador was present at the meeting and expected to speak after council members.
"While all concerned seek to avoid an accidental escalation leading to conflict, the risk is being multiplied by misplaced overconfidence, dangerous narratives and rhetoric, and the lack of communications channels," Guterres cautioned.
Last week, his top political official, Jeffrey Feltman, traveled to Pyongyang for the first in-depth political exchange of views between U.N. and North Korean officials to take place in that country in almost eight years.
Feltman, the highest-ranking American at the U.N., told reporters earlier this week that he engaged in more than 15 hours of talks over several days with Foreign Minister Ri Yong Ho and Vice Minister for Foreign Affairs Pak Myong Guk. He did not request a meeting with Supreme Leader Kim Jong Un.
"The North Korean interlocutors agreed it was important to prevent war," Feltman said.