Secretary of State Mike Pompeo answers questions at a press briefing June 11, 2018 in Singapore. Pompeo answered a range of questions related primarily to the historic meeting between U.S. President Donald Trump and North Korean leader Kim Jong-un scheduled for tomorrow June 12 in Singapore.

U.S. Secretary of State Mike Pompeo delivered on Monday a firm declaration of American intentions for the upcoming summit between President Donald Trump and North Korean leader Kim Jong Un.

"This is truly a mission of peace" Pompeo told members of the media assembled in Singapore, saying that talks were moving quickly with North Korean officials.

The closely watched American diplomatic effort — which will culminate Tuesday morning when Trump and Kim make history as the first sitting U.S. and North Korean leaders to meet — is entirely focused on achieving one goal, Pompeo said: Pyongyang's denuclearization.

"North Korea has previously confirmed to us its willingness to denuclearize, and we are eager to see if those words prove sincere," Pompeo said. "The fact that our two leaders are sitting down face to face is a sign of the enormous potential to accomplish something that will immensely benefit both of our peoples and the entire world."

The secretary of state said the U.S. is "hopeful" the summit will "set the conditions for future productive talks."

Still, the Trump administration official acknowledged that agreements with Pyongyang have fallen apart before.

"In light of how many flimsy agreements the United States has made in previous years, this president will ensure that no potential agreement will fail to ultimately address the North Korean threat," he said, emphasizing that the "ultimate" U.S. objective remains "the complete, and verifiable, and irreversible denuclearization of the Korean Peninsula."

That, he said, is "the only outcome that the United States will accept." In fact, sanctions will remain on the pariah state until that full and verifiable denuclearization has come to pass, Pompeo declared.

On the other hand, if diplomacy "does not move in the right direction," then those punitive measures will increase, he added.

Many analysts have suggested that the discussion about denuclearization means very different things to North Koreans than it does to American officials. That is, experts suggest Pyongyang may only agree to give up its nukes in exchange for the U.S. terminating its military presence in South Korea and ending its regional nuclear umbrella, a security arrangement in which Washington promises in-kind retaliation on behalf of close allies if they are attacked with nuclear weapons.

Pompeo appeared to address that sort of North Korean concern on Monday, saying "President Trump recognizes Chairman Kim's desire for security and is prepared to ensure a North Korea free of weapons of mass destruction is also a secure North Korea."

Responding to a reporter's question on the subject, the secretary of state added that the U.S. is "prepared to take actions that will provide [North Korea] sufficient certainty that they can be comfortable that denuclearization isn't something that ends badly for them."

That statement directly addressed a primary North Korean worry: The country has explicitly expressed concern that it could face "the destiny of Libya or Iraq which had been collapsed due to yielding the whole of their countries to big powers."

Libya voluntarily gave up its nuclear ambitions in 2003 in order to get out from under economic sanctions. The country's dictator Moammar Gadhafi was eventually overthrown in a Western-supported coup and killed in 2011.

For more CNBC coverage of the Trump-Kim summit, check out these analyses:

—CNBC's Nyshka Chandran contributed to this report.