The United States has confirmed Secretary of State Hillary Clinton will travel to the Cook Islands this week.

Rumours of her attendance came after news of security preparations were made public.

This morning a statement said Clinton would be travelling to the Cook Islands, Indonesia, China, Timor-Leste, Brunei, and Russia.

She is due to be in Rarotonga on Friday local time, (Saturday NZT).

Spokeswoman Victoria Nuland said Clinton would lead the biggest US delegation to ever attend the Pacific Islands Forum.

"Secretary Clinton will attend the Pacific Islands Forum Post Forum Dialogue on August 31 as part of our intensive engagement and ongoing collaboration with the Pacific Islands."

Her trip would emphasize the depth of the US relationship and interest in the economy, people, environment and security interests.

"The visit also represents a concerted effort to strengthen regional multilateral institutions, develop bilateral partnerships, and build on alliances – three core elements of US strategy toward the Asia-Pacific," Ms Nuland said.

Prime Minister John Key leaves for the Cook Islands this morning.

He was expected to meet with Clinton on Saturday morning, NZT.

- © Fairfax NZ News