South Korea Estimates North Korea Has Up to 120 Nuclear Warheads, Far Above Trump's Figure

South Korea has assessed that North Korea possesses up to 120 nuclear warheads, according to a Reuters report published Thursday — a number that stands in sharp contrast to the far lower figure President Trump has cited publicly as his administration pursues a fresh diplomatic opening with Kim Jong Un.

The gap between Seoul’s estimate and Washington’s framing is more than a statistical discrepancy. It goes to the heart of what any eventual deal with Pyongyang would have to address, and how difficult verification would be.

What Seoul Is Saying

South Korea’s assessment, reflecting the view of its intelligence services, places the total warhead count somewhere in the range of up to 120. That figure tracks with independent analyses from nonproliferation researchers, who have long argued that Pyongyang’s weapons program has advanced considerably faster than outside observers initially projected.

North Korea has conducted six nuclear tests since 2006. Its most recent, in 2017, was assessed by U.S. intelligence as producing a thermonuclear yield in the hundreds of kilotons range. Since then, satellite imagery has shown continued activity at the Yongbyon nuclear complex, and Pyongyang has declared its status as a nuclear-armed state in its constitution.

Seoul has had strong incentives to monitor the arsenal closely. South Korea sits within range of the full spectrum of North Korean delivery systems, from short-range ballistic missiles to intercontinental-range weapons capable of reaching the continental United States.

The Trump Factor

The discrepancy with Trump’s stated figure matters because the president has publicly downplayed the scale of North Korea’s nuclear program at key moments in past and current diplomacy. If Washington enters negotiations operating from a significantly lower baseline than Seoul’s intelligence suggests, the risk is that any early-phase deal locks in inadequate disclosure requirements.

As previously reported, Trump has signaled openness to a direct meeting with Kim Jong Un, reviving the personal-summit approach that defined his first term. North Korea test-fired ballistic missiles earlier this week in a move analysts read as Pyongyang signaling its continued military posture even as diplomatic channels stay open.

The timing of Seoul’s public assessment — released as Trump’s team pursues engagement — reflects a familiar dynamic: South Korea using public intelligence disclosures to shape the parameters of any deal before Washington can lock in terms that might leave Seoul exposed.

Verification Is the Core Problem

Even if Trump and Kim were to agree on a framework for denuclearization, the verification challenge is substantial. An arsenal of up to 120 warheads, distributed across a mountainous country with an extensive underground tunnel network, is not easily subject to snap inspections.

Past agreements, including the 1994 Agreed Framework and the 2005 Six-Party Talks joint statement, collapsed in part because of disputes over what Pyongyang was required to disclose and what inspectors were permitted to see. North Korea’s nuclear program was smaller and less advanced during those eras. The stakes of a failed verification regime are considerably higher now.

China, which shares a border with North Korea and has historically been the closest thing to a patron Pyongyang has, has been actively engaged in the diplomatic moment, with Foreign Minister Wang Yi visiting Seoul earlier this week for talks that included North Korea’s trajectory. Beijing has its own interest in a stable peninsula but has consistently resisted the kind of intrusive verification measures the United States considers a minimum standard.

Regional Implications

South Korea’s assessment reinforces what many defense analysts have argued for years: that any denuclearization framework that does not account for a three-digit warhead count is starting from an unrealistic baseline.

Japan, which has publicly supported Trump’s diplomatic outreach while quietly worrying about being excluded from any bilateral deal, is also watching the intelligence picture closely. Tokyo faces the same verification concern as Seoul: a deal that leaves warheads undeclared is not meaningfully different from no deal at all.

The Biden administration’s approach had been to insist on complete, verifiable, irreversible denuclearization as a precondition for substantive talks — a position Pyongyang rejected consistently. Trump has shown more flexibility about sequencing, suggesting he is open to incremental confidence-building measures. Whether that flexibility helps produce an agreement, or produces an agreement that Seoul and Tokyo view as insufficient, is the central question that Seoul’s warhead estimate puts on the table.

For now, the gap between Seoul’s intelligence picture and Washington’s public framing suggests that if negotiations do advance, the hardest arguments will be about the starting inventory — how many warheads North Korea has, where they are, and what counting them would even look like in practice.

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