The head of the U.S. Navy said he’s not particularly concerned that a Russian destroyer has joined a Russian intelligence ship off Hawaii during Rim of the Pacific exercises.

The destroyer arrived within the past few days coinciding with the start of the at-sea phase of the world’s largest international maritime exercise, the Navy said.

“We’ve got to be … alert to them, for sure, and aware … but to be honest, (I’m) not too concerned,” Chief of Naval Operations Adm. John Richardson said Friday.

“To be pretty straightforward, it’s kind of what we expect, right?” Richardson added. “This is a very interesting exercise. There are a lot of things going on. We know there are a lot of people interested. Russia is among them.”

The top officer in the Navy made the comments after an “all-hands” question-and-answer session with more than 400 sailors and Marines at Sharkey Theater at Pearl Harbor.

Richardson is on his way to China today to meet with People’s Liberation Army Navy commander Adm. Wu Shengli. It’s Richardson’s first visit to China as chief of naval operations, and it will be the first in-person meeting for the two leaders, the Navy said.

The U.S. Pacific Fleet confirmed last week that Russia had sent a Balzam-class auxiliary general-intelligence ship to operate in international waters off Hawaii.

The last time a Russian spy ship stopped by Hawaii was in 2004, also coinciding with RIMPAC, Pacific Fleet said.

Russia last participated in RIMPAC in 2012, U.S. Pacific Fleet spokesman Lt. Clint Ramsden previously said. The country was invited in 2014 but declined, he said. Russia, at odds with the West over its annexation of Ukraine’s Crimean Peninsula, wasn’t invited this year.

Russia’s AGI ship was outside the U.S. 12-nautical-­mile territorial waters but within the U.S. 200-nautical-mile exclusive economic zone. The destroyer joined the Russian spy ship in international waters.

The Pacific Fleet said the presence of the two Russian ships has not affected the conduct of RIMPAC.

Twenty-six nations, 45 ships, five submarines, more than 200 aircraft and 25,000 personnel are participating in the biennial exercise running to Aug. 4, mostly in and around the Hawaiian Islands but also off Southern California.

China, a participant in RIMPAC with five ships, has not sent a surveillance ship to monitor RIMPAC as it did in 2012 and 2014, Pacific Fleet said.

Richardson, a former commander of the submarine USS Honolulu who spent six years stationed in Hawaii, flew out to the big amphibious ship USS America on Friday.

In Beijing he is expected to visit the People’s Liberation Army Navy headquarters and meet with other senior Chinese defense officials.

In Qingdao, home of the Chinese North Sea Fleet, Richardson is scheduled to visit the Chinese navy’s submarine academy and tour the aircraft carrier Liaoning.

The U.N. Permanent Court of Arbitration recently angered China by rejecting the rising Asian power’s sweeping sovereignty claims in the South China Sea, leaving many to wonder what China’s next step will be.

The USS Ronald Reagan carrier strike group was on patrol in the South China Sea as of Wednesday, even as the five Chinese navy ships have been in Pearl Harbor for RIMPAC. It is the second time China was invited to participate in the exercise.

Richardson said China’s participation in RIMPAC and his visit to China shows it “continues to be important to keep those lines of communication open.” The military-to-military relationship with China is “very important to maintaining steady course and speed, if you will, in our relationship as two nations.”

In many areas the military relationship with China “is very healthy, very positive, very supportive, mutually reinforcing,” the chief of naval operations noted.

“In other areas we have some issues, right?” Richardson said. “And so we just have to be very honest with one another. I look forward to a very frank discussion with my (Chinese) counterpart about that.”

Richardson spent a few minutes addressing the assembled sailors and Marines at the all-hands call but said, “What I’m really interested in is hearing what’s on your minds.”

Housing allowances, a shortage of cryptologic linguists, physical fitness standards and the integration of transgender service members were some of the topics raised. One sailor said it takes 1-1/2 years to fully train a linguist.

“It’s got my attention because we’ve been stressed there,” said Richardson, adding that entire strike groups can be ready to go, but parts of their mission can be “pretty significantly degraded” because of a linguist shortage.

“We’re doing everything we can to kind of build a cadre of linguists,” Richardson said.

One sailor noted the tensions with China and NATO’s decision to deploy 3,000 to 4,000 troops to northeastern Europe to deter Russia.

“It’s a very dynamic environment out there right now, right?” Richardson said. “The players on the world stage are changing very quickly.”