Mike Pompeo said he's got high hopes for his latest meeting with North Korea's leader on Sunday (October 7).

It marks the U.S. Secretary of State's fourth visit to Pyongyang this year, with an aim for progress in Kim Jong Un giving up his nuclear weapons.

Before his arrival, he tweeted a photo of himself saying he and Kim would "continue our work to fulfill the commitments made by @potus and Chairman Kim at the #singaporesummit." Kim pledged at that meeting with President Donald Trump in June, to work toward the denuclearization of the Korean peninsula.

Washington has demanded Kim take irreversible steps to completely give up its arsenal.

So far, the Supreme Leader's fallen short of that this year and it has left the two sides in a diplomatic stalemate.

South Korea has suggested to break the deadlock, Pompeo should avoid his previous demands for an inventory of North Korea's nuclear weapons.

However, when asked last week about his negotiation plans on Sunday, Pompeo declined to give details.

Meanwhile, Trump has seemed interested in a second summit with Kim, who the president had glowing praise for last week.

(SOUNDBITE) (English)U.S. PRESIDENT DONALD TRUMP SAYING: "When I did it and I was really being tough - and so was he.

And we would go back and forth.

And then we fell in love, okay?" However, the two sides are far from a compromise.

Pompeo recently angered the North by saying global sanctions should stay in place until it gives up nuclear weapons.

Pyongyang's foreign minister told the U.N.

Last month those sanctions were deepening its mistrust of America and there was 'no way' it would give up its nuclear stockpile under such circumstances.

After leaving the North, Pompeo is set to visit South Korea and then Beijing.

Last week Pompeo said despite U.S. tension with China, they will be - quote - 'part of the solution' to the North Korean crisis.