WASHINGTON – Defense Secretary Jim Mattis is seeking to nominate the head of U.S. Fleet Forces Command to be the top U.S. military officer in the Pacific, according to three defense officials who spoke on background.

Adm. Phil Davidson’s nomination sits with the White House, officials said, which means that barring any objections he’ll relieve Adm. Harry Harris, who was nominated last week to be the U.S. ambassador to Australia. It also would mean that Davidson had fended off a strong challenge from the Air Force’s top officer in the Pacific, Gen. Terrence O’Shaughnessy.

An OSD spokesperson declined to comment for the article, saying “I have nothing to announce at this time.”

If Davidson is in fact nominated, the 1982 Naval Academy graduate will inherit a nuclear standoff with North Korea and a slow-motion conflict with China over its expansive claims of maritime rights in the South China Sea. Adm. Harris, the outgoing PACOM, developed a reputation for being aggressive with U.S. forces deployed in the region, including a major show of force in November where three aircraft carriers conducted a simultaneous patrol in the waters near the Korean peninsula.

Davidson has spent most of his career on the East Coast. He commanded the Eisenhower Carrier Strike Group, the cruiser Gettysburg and the frigate Taylor. Prior to being Fleet Forces commander, he commanded U.S. 6th Fleet in Europe. He has previous experience earlier in his career at a staff job at PACFLT, according to his official biography.

Davidson recently presided over the Navy’s Comprehensive Review of its Japan-based U.S. 7th Fleet after two deadly accidents claimed the lives of 17 sailors. Davidson’s review found widespread readiness issues and a culture that cut corners to meet the unrelenting demand for Navy ships in the region.

It is unclear if O’Shaughnessy is still under consideration, but sources said it was likely Davidson was the only name sent over. The Pacific Air Forces commander was the early favorite to replace Harris because of his extensive experience in the Pacific. But the post has always been a Navy admiral and many speculated that Senate Armed Services Committee Chairman Sen. John McCain would want to keep the post in Navy hands.