The United States deputy assistant secretary of defence for East Asia, Siddharth Mohandas, says the compact deals with the Federated States of Micronesia, Palau and the Marshall Islands demonstrates Washington's commitment in the Pacific is "ironclad".
Mohandas told the Senate's Energy and Natural Resources Committee the island nations of the Pacific play a critical role in America's strategic vision for the Indo-Pacific region.
He said the national security implications of the Compacts of Free Association - which are up for renewal this year - with the three north Pacific nations comes at a time of unprecedented US commitment to the Pacific.
He said the defence rights guaranteed by the compact agreements provide security not only for the compact states, but for the broader Pacific Islands region and for the US.
In May, the FSM and Palau signed off on a nearly final compact deals with US Presidential Envoy Joseph Yun. However, the Marshall Islands is calling for the US to provide adequate compensation to the nation for its nuclear legacy before renewing its compact.
Mohandas said having the compacts in place was vital to the Department of Defence's ability to deter aggression and, if necessary, prevail in conflict, ensuring peace, security and stability in the Indo-Pacific.
The compacts demonstrate the US's long-term commitment to Pacific Island partners and provide value across priority areas like assured access for bilateral and multilateral training, exercises and force posture, he said.
"We have made great progress toward renewing the compact agreements, and we've appreciated recent opportunities to engage with both Congressional members and staff on the importance of the renewal," Mohandas said.
"The defence rights guaranteed by the compact agreements provide security not only for the compact states, but for the broader Pacific Islands region and for the U.S. homeland, as well.
"The assured access guaranteed by the compact agreements protects the strategic approaches of the United States and allows us to operate freely in critical terrain in the Pacific."
According to the DoD, there are important bases in the region thanks to the compacts, including the US Army's missile defence testing site at Kwajalein in the Marshall Islands.