With North Korea refusing dialogue and ramping up its provocative missile tests, South Korea’s liberal President Lee Jae Myung is pushing for a step-by-step effort to end a decades-long standoff over the North’s nuclear program.

The goal, he said, would be first to halt advances in North Korea’s nuclear and missile capabilities, then to roll back its arsenal, and ultimately to move toward dismantlement.

Political and economic concessions would be offered for each progression forward.

This approach may face an uphill battle, as North Korea steadfastly refuses to engage in diplomacy over weapons it sees as the only security guarantee for the survival of its authoritarian leadership.

The North has recently ramped up weapons testing activities, despite U.S. President Donald Trump's recent push to resume diplomacy.

Lee will advance his plan during this week’s U.N. General Assembly meetings in New York, saying that both Seoul and Washington are willing to reengage with Pyongyang.

“To change the direction of a moving vehicle, it must be brought to a halt first,” Lee said in written responses to questions before his departure Monday for the United States.

“A phased approach of stopping, reduction and dismantlement is a practical way of effectively resolving the North Korean nuclear issue.”

Lee is slated to deliver an address before the U.N. General Assembly on Tuesday.

North Korea’s evolving nuclear program has raised questions about whether its nuclear disarmament can be achieved in a single step — or at all.

Trump said last month that North Korea has 57 nuclear weapons, while some experts say the North has more than 100 warheads.

Many have called for efforts to persuade North Korea to disarm in stages in exchange for economic and political benefits.

“Given how far North Korea’s nuclear and missile capabilities have advanced, it is not a realistic solution to wait until complete denuclearization can be achieved all at once,” Lee said.

“This is because, in the meantime, North Korea’s nuclear capabilities will continue to advance, escalating the threat.”

Lee recently pushed for talks aimed at formally ending the 1950-53 Korean War, saying that through such talks, ways to curb North Korea’s nuclear program could be explored.

There is concern among some that Lee’s approach would culminate in North Korea refusing to fully relinquish its nuclear program once it has secured what it seeks — such as sanctions relief.

To avert such an outcome, Lee said negotiators would need to demonstrate to North Korea that “moving toward stable and lasting peace is a realistic and feasible path to a secure and prosperous future.”

Irrespective of the approach adopted, it remains highly uncertain whether North Korea will resume talks in the near future.

When Trump, citing a “very good relationship” with North Korean leader Kim Jong Un, scaled back a major military exercise with South Korea last month, North Korea dismissed the U.S. president’s move, saying that just cutting parts of the drill won’t change its provocative nature.

Since then, Pyongyang has carried out three rounds of weapons launches and has repeatedly denounced what it terms U.S. hostility.

Experts contend that North Korea is likely seeking more substantial concessions from the United States.

Lee, who hopes that a resumption of Trump-Kim diplomacy would lead to reopening dialogue between the two Koreas, called Trump’s action “a deliberate step to send a clear message that the United States has no hostile intent toward North Korea.”

He said that both South Korea and the United States “remain open to engaging in dialogue with North Korea without preconditions.”

"What is required at this juncture is a political decision at the leaders' level.

The two leaders ought to cultivate trust and collaborate in order to identify common ground, face-to-face," Lee said.

Trump’s social media post regarding the downsizing of the exercise was made without prior consultation with South Korea.

It also referenced what Trump characterized as Lee’s refusal to join the United States in the “denuclearization” of Iran.

This provoked concerns regarding the U.S.-South Korea alliance.

Lee acknowledged that Trump’s decision had come “somewhat unexpectedly.”

However, Lee said that Trump had expressed his commitment to creating conditions that would lead to dialogue and that he wanted to reduce confrontation on the Korean Peninsula.

Lee said that the strategic interests of South Korea and the United States are deeply connected across many areas, and that he plans to build a more mutually beneficial partnership for the rest of Trump’s term.

For example, Lee said that planned cooperation in shipbuilding will not only revitalize U.S. shipbuilding and naval power, but also create new growth opportunities for South Korean businesses.

Lee stated on Friday that he would not allow his military to be drawn into the Iran war.

He indicated that his government was contemplating expanding the operations of a naval unit stationed in the Gulf of Aden to safeguard South Korean vessels and oil shipping routes.

Lee was anticipated to meet with Trump on the margins of the U.N. General Assembly.

When asked about the prominent teenage daughter of the 42-year-old North Korean leader, Lee said that his government had taken note of “her rising status” and was keeping all possibilities open.

"Nevertheless, I think we must exercise caution when it comes to articulating a definitive position at this juncture," he said.

South Korea’s intelligence agency has repeatedly portrayed her as Kim’s probable successor, though some experts contest this assessment, pointing to North Korea’s male-dominated power hierarchy.