Trump's visit to the base will highlight South Korea's role in sharing the burden of the alliance, the official said.

"The South Korean government paid the vast majority of the costs for building that base and repositioning some of the US forces and their families on the peninsula," he explained.

Moreover, it is becoming "a little bit of a cliche" to visit the DMZ, the official added. Since the Trump administration came into office, Vice President Mike Pence, Secretary of State Rex Tillerson and Defense Secretary Jim Mattis have all gone to the heavily fortified border.

Trump's visit will include bilateral talks with South Korean President Moon Jae-in and a speech before the National Assembly. Security and trade are expected to top the agenda, as in other countries throughout Trump's 12-day swing through Asia.

Seoul and Washington have already agreed to address US concerns about their bilateral free trade agreement, the official noted, and will continue those discussions during the presidential visit.

Meanwhile, Trump still believes in using diplomacy to rein in the North Korean threat, the official maintained.

"The president did not tweet that diplomacy is a waste of time. He tweeted that direct talks with North Korea was a waste of time," he said, citing the administration's campaign to pressure other countries to cut off ties to the regime.

Trump drew criticism last month after he tweeted that Tillerson was wasting his time trying to talk with North Korean leader Kim Jong-un.

"Direct talks with North Korea are unwise at this time and for the foreseeable future," the official said, "absent significant change in behavior by the regime."

"I would add to that that this administration from its earliest days made clear that the door was open for substantive dialogue with North Korea," he continued. "North Korea has shown zero inclination to engage in substantive talks with anyone in the world on this subject -- not with South Korea, not with the United States, not even with China."

Trump will use his trip to Beijing, immediately on the heels of the Seoul visit, to seek China's cooperation in putting further pressure on Pyongyang, the official said. (Yonhap)