Hawaii and Pacific commanders in Asia

Two of the highest-­ranking military commanders in Hawaii and the Pacific were in Asia on Tuesday for an exercise geared toward war on the Korean Peninsula and to deal with an alarming four U.S. Navy ship accidents this year in the western Pacific — including two fatal collisions in nearly as many months.

Multiple media outlets reported that the three-star head of the Japanese-based 7th Fleet, Vice Adm. Joseph Aucoin, will be relieved of duty.

U.S. Pacific Fleet commander Adm. Scott Swift was in Singapore on Tuesday to oversee efforts to recover 10 missing sailors after the guided-missile destroyer USS John S. McCain collided with an oil tanker near Singapore on Monday.

At a news conference, Swift said he would be traveling today to Yokosuka, Japan, where the warship is based, “for discussions with 7th Fleet leadership and engage with the families of USS John S. McCain there.”

Adm. Harry Harris, head of U.S. Pacific Command at Camp H.M. Smith, held a news conference Tuesday in South Korea with U.S. Forces Korea commander Gen. Vince Brooks and Gen. John Hyten, commander of U.S. Strategic Command, as the annual Ulchi Freedom Guardian exercise got underway.

North Korea vowed “merciless retaliation” for the drills, which it regularly claims are an invasion rehearsal and the United States says are for the defense of South Korea.

Several dozen Hawaii-­based soldiers are participating in Ulchi Freedom Guardian, both on Oahu and in South Korea.

Harris sought to tamp down any notion that U.S. forces were in disarray as tensions remain high with North Korea following its threat to launch missiles near Guam.

“Perception is in the eyes of the beholder, and I will hope that no one will test the U.S. on the perception that we’ve had a problem with USS John McCain and three other assets. That would be a very foolhardy thing to do,” CNN quoted Harris saying at the news conference.

About 17,500 U.S. service members are participating in the annual Ulchi Freedom Guardian, which started Monday and runs through Aug. 31. The joint U.S.-South Korean, computer-simulated exercise is focused on command post operations and an integration of effort.

“This right now is an exercise to make certain that we’re ready to defend South Korea and our allies over there,” U.S. Defense Secretary Jim Mattis said in a release Sunday.

A spokesman for the North Korean People’s Army said Tuesday that the military drill was a rehearsal to invade the North “in collusion with the South Korean puppet warmongers.”

“High-ranking bosses of the U.S. imperialist aggressor forces flew into South Korea to hold a war confab. Such huddle is increasing the gravity of the situation,” the statement said.

The destroyer McCain, named for the father and grandfather of the current U.S. senator, collided with the Liberian-flagged 600-foot oil and chemical tanker Alnic MC east of the Strait of Malacca at 5:24 a.m. Monday. The collision left a gaping dent and hole in the destroyer’s hull, and flooded crew berthing and machinery and communications rooms.

The destroyer arrived at Changi Naval Base in Singapore that afternoon.

“Right now we are still searching for our 10 missing sailors. That remains our focus,” Swift said.

U.S. Navy and Marine Corps divers were able to access sealed compartments in damaged portions of the ship and to recover “some remains,” Swift said. The Malaysian navy also reported it had located potential remains.

Investigations continue, meanwhile, into the June 17 collision of the destroyer USS Fitzgerald and merchant vessel ACX Crystal off Japan. The Navy recently released harrowing details of crew members’ efforts to escape a rapidly flooding berthing compartment in waters that were first up to their waists, then to their necks and then quickly submerged the entire compartment.

The 728-foot container ship’s bulbous underwater bow punched a 13-by-17-foot hole in the Fitzgerald’s second and third decks below the main deck at 1:30 a.m., allowing seawater to rush into Berthing 2, an area with 42 beds spanning the width of the ship. Seven sailors on the Yokosuka-based Fitzgerald were killed.

Additionally, the guided-missile cruiser USS Antietam ran aground Jan. 31 while it was anchoring near Yokosuka base, the home of the 7th Fleet. And on May 9 a South Korean fishing boat collided with the San Diego-based cruiser USS Lake Champlain off the Korean Peninsula.

Adm. John Richardson, chief of naval operations, said in a video message to the fleet Monday that he was “devastated and heartbroken” to hear about the collision and missing sailors.

Richardson noted it was the second collision in three months and the latest in a series of such incidents in the Pacific theater.

“This trend demands more forceful action,” he said. As such, Richardson directed an “operational pause to be taken in all our fleets around the world” to refocus on safety and effective operations.

Additionally, he directed a more comprehensive review “to ensure that we get at the contributing factors — the root causes of these incidents.”

Swift, in a message to commanders, noted that “we have experienced a series of unfortunate incidents, some of which have claimed the lives of our shipmates, while conducting the most basic of operations.”

He directed that each command in the Pacific take a full workday dedicated to an “operational pause” to focus on fundamentals and to be completed by Monday. Swift said he expects “full participation by the chain of command. There can be no bystanders.”

Carl Schuster, a retired Navy captain and adjunct professor at Hawaii Pacific University, said the pattern of ship incidents is a concern, but not a crisis.

“It boils down to, what are the causes that we need to look at? What are we doing as a practice that’s wrong, or potentially wrong?” he said. “So they are going to look at training records, they are going to look at qualification standards, and qualification records, particularly for watch-standers.”

The Navy also can get a ship accident pattern like this “when we go from low tempo to high tempo,” Schuster said. “Right now the fleet is overstretched. They’ve got more commitments than they have warships and crew to cover. We also had a maintenance shortfall over the last few years. So what you’ve got is crews going to sea with a more compressed training program.”

The Associated Press contributed to this report.