The United States on Monday established diplomatic ties with the Cook Islands and Niue, in a move widely seen as part of efforts to roll back China's expanding influence in a strategically important region.

The formal relations were forged as U.S. President Joe Biden hosted a meeting with Pacific islands leaders in Washington to boost cooperation in areas that matter most for them, including infrastructure building and steps to combat climate change and illegal fishing.

"The United States is committed to ensuring an Indo-Pacific region that is free, open, prosperous, and secure," Biden said as he met with them for the second summit with the Pacific Islands Forum. "We're committed to working with all the nations around this table to achieve that goal."

U.S. President Joe Biden (R) talks with Papua New Guinean Prime Minister James Marape (L) and Cook Islands Prime Minister Mark Brown as they stand for a family photo with Pacific Islands Forum leaders at the White House in Washington on Sept. 25, 2023. (AP/Kyodo)

Biden said the United States will increase assistance for risk reduction for climate and natural hazards as the Pacific islands states are especially vulnerable to rising sea levels, and invest more in projects to contribute to the improvement of infrastructure and the sustainability of fisheries.

For such initiatives, Biden said he will request the U.S. Congress endorse about $200 million in additional funding after Washington last year committed to $810 million in support for the countries.

U.S. officials said that one of the main projects is to provide secure undersea cable connectivity for the countries, given that internet connections are still not as reliable as they hope.

Biden also said the United States will double the number of academic exchanges for Pacific islands students.

Cook Islands Prime Minister Mark Brown, the current chair of the forum, hailed the establishment of diplomatic ties between the United States and his country as well as Niue.

Brown described the two acts of diplomatic recognition as "milestones" that serve to "celebrate eras of change and demonstrate that with unshakable resolve and leadership, remarkable achievements are possible."

Before concluding the two-day summit through Tuesday, the leaders released a joint statement pledging that they will work together "in genuine partnership, rooted in mutual respect, consistent with the principles of the U.N. Charter, and in the spirit of transparency and accountability."

The leaders agreed to hold the next summit between the United States and the 18-member forum, including Australia, Fiji, New Caledonia, Papua New Guinea, Samoa and Tonga, in 2025, according to the statement.

Biden hosted the inaugural summit with the forum's leaders almost a year ago in Washington and unveiled the first-ever U.S. strategy dedicated to the Pacific islands, which warned that "pressure and economic coercion" by China risked undermining the peace and prosperity of the region.

Although the United States has been stepping up efforts to curtail increasing Chinese inroads into those countries, Solomon Islands Prime Minister Manasseh Sogavare skipped the second summit.

The Solomon Islands, which switched its diplomatic recognition from Taiwan to Beijing in 2019, has signaled a tilt toward China and Sogavare's no-show came even though he addressed the U.N. General Assembly in New York late last week.

"We're disappointed that he has chosen not to come to this very special (summit)," a senior Biden administration official said.

The second summit was initially slated for May in Papua New Guinea. At the time, Biden scaled back his travel plans due to a potential debt default back in Washington, returning home after a Group of Seven summit in Japan and passing up a chance to become the first sitting U.S. president to visit Papua New Guinea.