The United States reopened its embassy in the Solomon Islands Thursday after a 30-year hiatus, part of a bid to counter China's growing influence in the South Pacific.

Re-establishing the diplomatic outpost was a renewal "of our commitment to the people of Solomon Islands and our partnerships in the Indo-Pacific region", US Secretary of State Antony Blinken said in a statement.

The US closed its embassy in the capital Honiara in 1993 after the end of the Cold War led to a reduction in diplomatic posts and a shift in priorities.

Washington signalled its intent to re-establish a Honiara embassy in early 2022 before the Solomons signed a secret security pact with China.

The deal, penned by Prime Minister Manasseh Sogavare and Beijing, sparked fears among Western powers that the Solomons could provide China with a new foothold in the Pacific.

US diplomat Russell Corneau, the interim representative in Honiara, said the American embassy would "serve as a key platform" between his government and the Solomons.

Blinken added that the reopening "builds on our efforts to place more diplomatic personnel throughout the region and engage further with our Pacific neighbours".

Sogavare did not attend the opening ceremony, but foreign affairs secretary Colin Beck said the embassy's reopening was "welcomed by the government and people of the Solomon Islands".