The United States says it is "disappointed" by the absence of Solomon Islands' prime minister from a two-day summit aimed at improving Washington's ties to the region.
Members of the Pacific Islands Forum (PIF) gathered for the second year in a row at the White House, where President Joe Biden urged leaders to "recommit to each other".
"Because with the past as our proof, we're stronger and the world is safer when we stand together," he said.
The US is working to boost its presence in the Pacific Islands, after publicly conceding it had not focused enough attention on the area while China's influence expanded.
But in a blow to those diplomatic efforts, Solomon Islands' Prime Minister Manasseh Sogavare declined to travel on to Washington after visiting New York City last week for the United Nations General Assembly.
"I think it'd be fair to say that the United States is disappointed," a senior administration official told reporters on a background briefing.
"We're disappointed that he has chosen not to come to this very special PIF Summit between the United States and the Pacific Island nations."
A Solomon Islands government official told the ABC that Mr Sogavare needed to attend to "domestic issues" in Honiara and that the invitation from the White House came after parliamentary business had been set.
The secretary of Solomon Islands' foreign affairs ministry, Collin Beck, is attending the summit in Mr Sogavare's place.
Vanuatu's prime minister Sato Kilman is also absent from the summit, however the US said he needed to be present for a no-confidence motion taking place in the country's parliament.
Solomon Islands' ties to China
The relationship between Solomon Islands and China has prompted concern in both Washington and Canberra, particularly after the two countries signed a secretive security pact last year.
Mr Sogavare attended last year's summit in Washington but initially resisted signing a joint declaration being issued between the US and Pacific Island leaders.
He has since visited China to meet President Xi Jinping, and last week told the UN General Assembly of his country's increasingly close ties to Beijing.
"Solomon Islands is grateful and appreciates the ongoing support from our bilateral and multilateral partners, in particular the People's Republic of China, who has become our leading infrastructure partner," he told the meeting.
Asked whether China had motivated increased engagement with the Pacific Islands, the Biden administration official appeared to agree that it had.
"No question that its [China's] assertiveness and influence, including in this region, has been a factor that requires us to sustain our strategic focus," they said.
"But what we're really focused on doing is showing our Pacific Island friends that the United States, working with like-minded partners, can provide viable alternatives that will work for Pacific Island nations."
US formalises new diplomatic relationships
The White House used the Pacific Islands summit to announce it had formally begun recognising Cook Islands and Niue as "sovereign and independent" states, meaning diplomatic relations will begin with both.
"These milestones celebrate areas of change, and demonstrate that with unshakeable resolve and leadership, remarkable achievements are possible," said Cook Islands Prime Minister Mark Brown.
He also urged the United States to "actively engage" at the highest level, pointing to an upcoming forum meeting in Rarotonga, Cook Islands in November.
"Engagement cannot be restricted to annual summits," Mr Brown said.
"It must be year-long efforts, working to an agreed plan of action and supported by requisite resources to deliver transformative action on the ground."
The US is also promising nearly $US200 million ($311 million) for new projects and activities, including undersea cables to improve internet connectivity in the region.
"Our objective is to build a better world, one of the great opportunities for security, prosperity and dignity for all our people, no matter where they live," Mr Biden told leaders.
"That starts by building stronger partnerships with each other."
The Pacific Islands leaders stopped in Baltimore on their way to Washington, attending an American football game and visiting a Coast Guard facility.
They are also expected to attend a roundtable focused on climate change, and meet Secretary of State Antony Blinken and Treasury Secretary Janet Yellen before wrapping up their visit.
Story first published on ABC News