"The partnership between our two nations and our two people is deep and enduring," Trump said. "We have been proud to stand by your side for many decades as an unwavering friend and a loyal ally. And you have never had a time where this ally has been more loyal or stood by your side more than right now."

Trump will travel to Seoul from Osaka, Japan, where he is currently attending a Group of 20 summit and meeting with world leaders over a wide range issues including security and trade.

He will hold talks with South Korean President Moon Jae-in on North Korea's nuclear weapons program, the bilateral alliance and trade issues.

"Today, President Donald J. Trump is visiting the Republic of Korea (ROK) to reaffirm a vital partnership that is essential to our economic and security interests," the White House said.

"The United States and the ROK are key partners that share deep historical, security, and economic ties. Our vital partnership is based on the shared principles of democracy, human rights, and the rule of law," it added.

The White House also described the bilateral alliance as the "linchpin" of peace, security, and prosperity in the Indo-Pacific region.

"This visit will advance and strengthen economic and security cooperation between our two nations," it said.

Moon and Trump are expected to discuss ways to revive denuclearization talks with North Korea that have stalled since the second summit in February between the US president and North Korean leader Kim Jong-un ended without a deal.

Trump is working closely with Moon to achieve the final, fully verified denuclearization of North Korea and to establish a lasting peace on the peninsula, the White House noted.

"The United States and ROK coordination and cooperation regarding the denuclearization of North Korea is the strongest it has ever been," it said.

"President Moon has been indispensable in assisting with President Trump's negotiations with North Korean Chairman Kim Jong Un."

The White House said both Moon and Trump want a prosperous and peaceful future for North Korea under Kim's continued leadership.

The comment is a reference to the economic rewards both have promised in exchange for denuclearization as well as US guarantees for regime security.

On the South Korea-US economic relationship, the White House credited Trump with securing "significant improvements" to the bilateral free trade agreement, known as the KORUS FTA.

Under the Trump administration, the two sides revised the deal to include the doubling of the number of American cars that can be exported to South Korea without further modification.

Thanks to Trump, the White House said, the US goods trade deficit with South Korea dropped by 23 percent last year from the previous year.

It will be Trump's second visit to South Korea since taking office. The first was in November 2017.

(Yonhap)