Vice President Kamala Harris will look to bolster economic and military cooperation in China’s backyard as she visits Singapore and Vietnam starting this weekend, in the Biden administration’s most high-profile trip yet to Asia.

The White House has been on the diplomatic offensive in Southeast Asia after years of passive U.S. engagement, recently sending top diplomats to the region along with COVID-19 vaccines that have accounted for about a fifth of the 111.7 million doses it donated globally.

In addition to securing a key military deal with the Philippines in July, the approach signals a more assertive posture in a part of the world that has grown more economically dependent on Beijing.