HANOI (Reuters) -- Vice President Kamala Harris pushed ahead with a trip to Vietnam on Tuesday after delaying the visit over concerns due to an unexplained health incident potentially related to the mysterious Havana Syndrome.
Harris, eager to woo allies in a bid to counter China, arrived in the Southeast Asian country's capital after a three-hour delay in Singapore and an unusual statement from the U.S. Embassy in Vietnam blaming "a recent possible anomalous health incident" for the delay.
"Anomalous health incident" is a term the U.S. government often uses to describe Havana Syndrome, a condition with symptoms such as dizziness, nausea, migraines and memory lapses, so named because it first was reported by American officials based in the U.S. embassy in Cuba in 2016.
"The Vice President's office was made aware of a report of a recent possible anomalous health incident in Hanoi, Vietnam," the U.S. Embassy statement said.
"After careful assessment, the decision was made to continue with the Vice President's trip," the statement said, without elaborating.
A spokesperson for Harris declined to comment on the reason for the delay.
Some 200 U.S. officials and kin, including CIA officers, have been sickened by "Havana syndrome," CIA Director William Burns has said. A U.S. National Academy of Sciences panel in December found that a plausible theory is that "directed energy" beams caused the syndrome, he said.
The CIA sees a "very strong possibility" that the syndrome is intentionally caused, and that Russia could be responsible, but is withholding definitive conclusions pending further investigation. Moscow denies involvement.
The incident came as Washington faces icy relations with another global competitor, China.
As Harris's trip to Vietnam was delayed, Vietnamese Prime Minister Pham Minh Chinh held an unannounced meeting with Chinese Ambassador Xiong Bo, during which Chinh said Vietnam does not align itself with one country against any other.
Earlier on Tuesday, Harris had accused Beijing of coercion and intimidation to back claims in the South China Sea, her most pointed comments on China during a visit to Southeast Asia, a region she said was critical to U.S. security.
"The Prime Minister affirmed that Vietnam adheres to an independent, self-reliant, multilateral, and diverse foreign policy and is a responsible member of the international community," the Vietnamese government said in a statement.
"Vietnam does not align itself with one country against another," it said.
Territorial disputes in the South China Sea should be settled according to international law and "high-level common sense," it said. China would provide COVID-19 vaccine support for Vietnam, it added.
The U.S. administration has called rivalry with China "the biggest geopolitical test" of the century.
"The fact that China's ambassador insisted on a meeting with the Vietnamese prime minister shortly before Harris landed shows how anxious Beijing is that its communist neighbor may tilt toward the U.S.," said Murray Hiebert, a Southeast Asia expert at Washington's Center for Strategic and International Studies.
During the meeting, Chinh thanked the ambassador for a previously unannounced donation of 2 million COVID-19 vaccines. It was not immediately clear which vaccine China had donated.
Vietnam had successfully contained the coronavirus for most of last year but since April has been dealing with a large COVID-19 outbreak in Ho Chi Minh City, driven by the highly contagious Delta variant of the virus. Just under 2% of its 98 million people are fully vaccinated.