A US delegation led by Assistant Secretary of State for East Asian and Pacific affairs Daniel Kritenbrink, and the National Security Council’s (NSC) Indo-Pacific coordinator Kurt Campbell has landed in Honiara.

The high-level US delegation are in Honiara for discussions, a key concern being the recently signed security treaty between Solomon Islands and China.

Tarcisius Kabutaulaka, an associate professor at the University of Hawaii at Manoa, tells TIME that “the manner and timing of the announcement” are significant. “Beijing unilaterally announced the signing just ahead of the U.S. delegation’s visit to Solomon Islands,” he tells TIME. “I think that is not a coincidence.”

The security treaty included the potential deployment of Chinese security forces to maintain “social order” in response to requests from the government of the Solomons, raising concerns from US and its allies.

The U.S. closed its embassy in the Solomons capital Honiara 29 years ago, but in February this year pledged to reopen it.

With Time.com