The US State Department said on Thursday that Blinken will dedicate a new US embassy in the Tongan capital of Nuku'alofa on July 26 before heading to Wellington, New Zealand, where he will attend the women's football World Cup match between the US and the Netherlands.
Blinken will then have meetings with New Zealand officials and move on to Brisbane, Australia, for meetings with US Defense Secretary Lloyd Austin and their Australian counterparts on July 28-29.
The trip will be Blinken's third to Asia in the past two months - following a visit to China last month and a visit to Indonesia for talks with Southeast Asian officials just last week.
And, it comes as Treasury Secretary Janet Yellen and climate envoy John Kerry have recently wrapped up their own trips to China.
Second gentleman Douglas Emhoff is currently in New Zealand for the World Cup and will be making a side trip to Samoa in the coming days.
Blinken's travel was announced a week after the State Department notified Congress that it plans a massive increase in diplomatic personnel and spending for facilities at new US embassies in the Pacific islands.
The boost in the US presence in the Pacific is in response to China's increasing assertiveness there.
The update to Congress, which was obtained by the Associated Press, pointed out that China has permanent diplomatic facilities in eight of the 12 Pacific island countries that the United States recognises and said the US needs to catch up.
The department told lawmakers that it envisions hiring up to 40 staffers over the next five years for each of four recently opened or soon-to-be-opened embassies in the Pacific.
Those include the embassy in embassy in Nuku'alofa, an embassy in Honiara, Solomon Islands, that opened in January; and planned embassies in Port Vila, Vanuatu, and in Tarawa, Kiribati.
Currently there are only two temporary US staffers each in Honiara and Nuku'alofa.
At each of those posts, the department said it will spend at least $US10 million ($A15 million) for start-up, design and construction costs.
