US President Joe Biden is scheduled to arrive in Seoul on Friday for talks with South Korean President Yoon Suk Yeol, although administration officials admit they are concerned North Korea will attempt to overshadow the visit with the test launch of an intercontinental ballistic missile or even an underground nuclear test.
Biden is expected to discuss the security situation in Northeast Asia during his three-day visit, as well as ways to potentially engage with North Korea.
The US leader is due to travel on to Tokyo on Sunday for bilateral discussions with Japanese Prime Minister Fumio Kishida and a summit of the leaders of the Quadrilateral Security Dialogue, or Quad, which brings together Japan, the US, Australia and India.
North Korea's continued pursuit of weapons of mass destruction will likely dominate discussions in both capitals.
Addressing a press conference in Washington on Wednesday, US national security adviser Jake Sullivan said North Korea is likely to carry out a long-range missile test or what would be its seventh nuclear test at any time in the next few days.
"We are preparing for all contingencies, including the possibility that such a provocation would occur while we are in Korea or Japan," Sullivan said.
North Korea has already launched 16 missiles so far this year, many in the run-up to South Korea's general election in March.
Analysts have said the regime of Kim Jong Un sought to intimidate the incoming South Korean president, and wants to remain at the forefront of the US president's thinking.
"Regional security is going to be the main issue when Biden and Yoon meet," said Ahn Yinhay, a professor of international relations at Korea University in Seoul.
"There are concerns about the North's nuclear and missile capabilities and it would not surprise me at all if they did decide to carry out a test while Biden is in Japan, to act as a show of strength," she told DW. "Biden will be very keen to improve cooperation between the US, South Korea and Japan."