Harris will discuss regional security, the global response to Covid-19, climate change, and "our joint efforts to promote a rules-based international order," said spokesperson Symone Sanders.
Former US foe Vietnam has emerged as a key US partner and a vocal opponent of China's territorial claims in the South China Sea. Harris' trip will follow one that Defense Secretary Lloyd Austin made this week to Hanoi.
"President Biden and Vice President Harris have made it a top priority to rebuild our global partnerships and keep our nation secure, and this upcoming visit continues that work," the White House said in a statement outlining Harris's travel plans.
It did not give precise dates for her trip and diplomats said these were still being worked on.
In Vietnam on Thursday, Austin sought to nudge forward security ties that have been steadily deepening amid shared concern about China's activities in the South China Sea.
Austin also visited the Philippines and scored a significant success when its President Rodrigo Duterte restored a pact governing the movement of US troops in and out of the country, something strategically vital for US efforts to counter China.
Analysts said Harris's visit would be important to emphasize Washington's commitment to Southeast Asia, and several speculated it could result in more pledges of US vaccines to the region, which has been hit hard recently by Covid-19.
"The Austin visit this week was badly needed to show Southeast Asia that the US wants to engage," said Murray Hiebert, a Southeast Asia expert at Washington's Center for Strategic and International Studies.
"Austin was under pressure to deliver this message and Harris will do the same."
On Sunday, the United States shipped 3 million doses of the Moderna Covid-19 vaccine to Vietnam and it has sent doses to other Southeast Asian countries too, but an agreement it reached in March with Japan and Australia and India to provide a billion doses to the region stalled due to an Indian export ban.
Deputy Secretary of State Wendy Sherman visited Indonesia, Cambodia and Thailand in late May and early June and Japan, South Korea and Mongolia this month before heading to China for talks that appeared to do little to ease deeply strained ties.
President Joe Biden highlighted the threat Washington sees from China this week, saying that Chinese leader Xi Jinping was "deadly earnest about becoming the most powerful military force in the world, as well as the largest and most prominent economy in the world by the mid-40s, the 2040s."
On her first overseas trip in office, Harris visited Mexico and Guatemala in June with the aim of lowering migration from the region. During her trip she focused on issues such as economic development, food insecurity and women's issues.