Bloomberg has underscored this is being done to directly "counter" China: "President Joe Biden announced that the US would establish diplomatic relations with the Cook Islands as his administration seeks to strengthen ties with Pacific island nations and counter Beijing's growing influence in the region," a Monday report said.

Biden is currently hosting the leaders of Pacific Island nations in Washington D.C. for an event called the US-Pacific Island Forum Summit, and during the high-level talks said "the history and the future of the Pacific Islands and the United States are inextricably linked."

He explained: "The United States' recognition of the Cook Islands, and the establishment of diplomatic relations will not only strengthen the ties between our nations, it will help ensure that our shared future is more secure, more prosperous, and more free — for our people and people around the world."

The summit includes representation of the following countries: Australia, the Cook Islands, Micronesia, Fiji, French Polynesia, Kiribati, Nauru, New Caledonia, New Zealand, Niue, Palau, Papua New Guinea, the Republic of the Marshall Islands, Samoa, Solomon Islands, Tonga, Tuvalu, and Vanuatu - according to a press release.

Leaders from these countries were already in the United States throughout last week's UN General Assembly, and stayed for the key Pacific Island summit.

But one important nation did not, and its absence highlights growing regional tensions between Washington and Beijing: 

But the administration was "very disappointed" that Solomon Islands Prime Minister Manasseh Sogavare, who was in New York last week for the U.N. General Assembly, opted not to stick around for the White House summit, according to an administration official. The Solomon Islands last year signed a security pact with China.