US Defense Secretary Chuck Hagel has postponed a visit to Myanmar and Vietnam this month due to scheduling issues, including upcoming congressional hearings, a Pentagon official said on Tuesday.
Hagel had been expected to visit the Southeast Asian countries in the middle to the month.
He had been expected to attend a meeting of defense ministers of the 10-member Association of Southeast Asian Nations (ASEAN) in Myanmar, while the Vietnam leg was a bilateral visit following a US decision to relax a long-standing U.S. arms embargo on Hanoi.
"The decision to postpone the trip was driven by new and significant demands being placed on the Secretary's schedule, to include upcoming congressional hearings," a Pentagon official said.
"It would be pure fallacy to derive any other meaning from this postponement," the official said, adding that Hagel looked forward to rescheduling the trip.
Hagel's visit to Asia would have followed on from trips to the region by President Barack Obama to attend the Asia Pacific Cooperation forum and East Asia summits, and by U.S. Secretary of State John Kerry.
The United States has been working hard to boost defense ties with ASEAN countries in the face of a rising China, which has been increasingly assertive in its territorial claims in the region.
Last month, nearly 40 years after the end of the Vietnam War, the United States partially lifted a ban on lethal weapon sales to Vietnam, which has been sharply at odds with China over rival claims in the South China Sea, which Vietnam calls the East Sea.