President Trump must warn Kim Jong Un that new missile tests won't earn any relief from American sanctions. The need is newly urgent following the North Korean leader's latest missile tests on Thursday.

Fox News reports that at least one of the projectiles that was launched is a short-range ballistic missile. Although not an intercontinental ballistic missile of the kind that Kim has pledged he would suspend testing, the missile is new and represents a clear escalation for two reasons.

First, because the missile is a new system which makes public North Korea's ongoing ballistic missile research. Second, because North Korea intends Washington to assess this test as a precursor to new ICBM tests.

North Korean state media is making clear that unless the U.S. reduces its sanctions pressure, new ICBM tests will follow. This latest test is thus a calibrated nudge to persuade Trump to back off or face ICBM escalation. But the North Koreans are reluctant to actually start firing off ICBMs again. That would risk even greater U.S. sanctions pressure or military action. Kim Jong Un is hoping that Trump will reduce U.S. sanctions before an ICBM test becomes necessary.

Yet, an ICBM test is increasingly likely.

The Trump administration has rightly recognized that sanctions cannot be reduced without commensurate North Korean concessions. Seeing as none of those concessions have yet been offered, the sanctions must remain in force.

However, as I noted in May, a looming famine means that Kim needs to alter the status quo one way or another.

The U.S. should warn Kim that his escalation strategy will lead North Korea nowhere good. Instead, referencing South Korea's newly rediscovered resolve, Trump should make clear that Kim's only route to economic empowerment is to denuclearize. Trump should also make clear that there are ways that Kim can denuclearize without sacrificing his golden egg nuclear weapons (for example, by agreeing to store those weapons in an International Atomic Energy Agency facility on his soil). The key is Kim's verifiable disarmament of his ICBMs: removing his ability to launch nuclear warheads against every major American city.

That said, Trump must make clear that Kim's escalation is unacceptable. He must remind the North Korean despot that diplomacy is America's distinct preference, but also that America won't resort to appeasement.