By the end of 2002, North Korea expelled I.A.E.A. inspectors, followed by an official withdrawal from the NPT in 2003. China and Russia then joined Japan, the United States and South Korea to create the six-party talks with the North. Pyongyang again agreed to the verifiable denuclearization of the Korean Peninsula. But instead, it declared itself a nuclear power in 2005 and carried out a nuclear test in 2006. The five countries’ attempt to solve the problem through dialogue failed.

In short, while the international community provided North Korea with sanctions relief and support as “compensation” for its pledges, the regime ignored most of its commitments.

Considering this history and its continuing missile launches and nuclear tests, more dialogue with North Korea would be a dead end. Pyongyang would see more talks as proof that other countries succumbed to the success of its missile launches and nuclear tests. Now is the time to exert the utmost pressure on the North. There should be no more delays.

How could North Korea relentlessly pursue missile development and nuclear tests over almost half a century? How could North Korea, under successive United Nations sanctions for a decade, acquire enormous resources to obtain crude materials, components and powerful engines? Statistics show that there are countries, mainly in Asia, that continue trading with North Korea; and for some, as recently as in 2016, their trade even exceeded that of the previous year. According to the United Nations, foreign-made parts have been used in North Korea’s ballistic missiles. There are countries buying products and services from North Korea or accepting its workers. Front companies established in Asia enable North Korea access to foreign currencies.

Japan has responded by reaffirming the ironclad Japan-United States alliance, and Japan has coordinated in lock step with the United States and South Korea. I firmly support the United States position that all options are on the table.

As a response to the latest nuclear test, I value the swift and unanimous adoption of Security Council Resolution 2375 on Sept. 11, which puts significantly tougher sanctions on North Korea. But I stress that we must not be simply complacent with the adoption of these sanctions. We must thoroughly enforce the successive resolutions in order to prevent North Korea from obtaining the goods, technologies, funds and people to further develop its missiles and nuclear program.