NEWPORT, R.I. — Secretary of Defense Mark Esper today called for expanding base locations in the Pacific while continuing regular freedom of navigation operations in the region, as part of a broader attempt to stymie China’s influence.

Esper, speaking at the Naval War College, called the Indo-Pacific theater “our priority theater,” as the department continues its shift towards an era of great power competition.

“Many of you spent most of your career fighting irregular warfare or engaging with it,” Esper told the audience. “But times have changed.”

In the Pacific, “allies and partners want us to lead… but to do that we must also be present in the region,” Esper said. “Not everywhere, but we have to be in the key locations. This means looking at how we expand our basing locations, investing more time and resources into certain regions we haven’t been to in the past.”

The Secretary did not expand on what that may mean; reporters traveling with Esper were able to see his short opening speech but were not present for a question and answer session with students. But Patrick Cronin, a regional expert with the Hudson Institute, pointed to several possibilities for expanded bases in the Pacific.

“The U.S. is right to work on a more distributed set of access points throughout the Indo-Pacific in geographically strategic locations, where diplomatic and development support from the U.S. and allies and partners can ensure sustainable engagement to build capable partners and strengthen deterrence,” Cronin said. He pointed to Singapore and the Philippines as two classic allies who could stand to have U.S. presence built up. In addition, he identified Thailand’s U-Tapao Royal Thai Navy Airfield, as well as broad improvements in Vietnam.

“As Vietnam [and] U.S. celebrate 25 years of normalization next year, we need to keep expanding exercise activity and port visits,” he said. “And there are access arrangements, perhaps not as public, in Malaysia and Indonesia. Beyond defense, these are also areas where some development and investment can occur that is sought from the local countries and wins public-private support for the U.S. and like-minded partners.”

Looking further south, both the Federated States of Micronesia and the Commonwealth of Northern Mariana Islands are regions which have not received major attention from the Department of Defense in the past. While far from the strategic center of the region, the U.S. could seek to keep Chinese influence away from those island collections. Another option is Papua New Guinea, which is currently building a joint naval base with the U.S. and Australia.

Eric Sayers, a former special assistant to the head of U.S. Pacific Command, now with the Center for a New American Security, pointed to the islands of Yap and Palau as another area with “critical geography where the U.S. has exclusive access under our Compact agreements” from which U.S. Air Force assets could operate.

“This lets us diversify the locations we use, complicates PLA planning, avoids dependency on large bases that can become single points of failure, and buys down the diplomatic-political risk of relying too heavily on a place like the Philippines where we may only have access during a dispute that they are involved in,” Sayers said.

Later in his speech, Esper also called for a continuation of freedom of navigation operations, both in the region and elsewhere.

“It also means we have to continue to fly, sail and operate wherever international rules allow freedom of navigation, for both military and commercial operations, whether it’s the strait of Hormuz or the Malacca strait,” Esper said.