The Navy said in a news release the sailor assigned to the amphibious assault ship USS Boxer tested presumptive positive for COVID-19 on Friday, March 13, and was quarantined at home as of Sunday.
Test results are considered presumptive positive, pending confirmation by the Centers for Disease Control and Prevention, according to the Navy.
The Boxer, which has a crew of more than 1,200 sailors, is not at sea and currently in port at Naval Base San Diego where the vessel is based.
"Personnel that the individual immediately identified having close contact with have been notified and are in self-isolation at their residences," the Navy said. "None of them is aboard the ship currently."
Military health professionals are also investigating to determine whether any additional personnel may have been in close contact and possibly exposed to the sailor.
"Depending on the results of that investigation, additional mitigations may be taken," the Navy said.
Officials said U.S. Navy ships conduct daily, routine, daily cleanliness procedures geared toward health, wellness and the prevention of communicable disease spread.
In the wake of the sailor testing positive for COVID-19, the USS Boxer is "taking appropriate preventative measures and conducting a thorough cleaning in accordance with specific guidance from the CDC and Navy-Marine Corps Public Health Center," according to the Navy.
"Commander, Naval Surface Force, U.S. Pacific Fleet is committed to taking every measure possible to protect the health of our force," the service said. "We remain in close coordination with state and federal authorities, and public health authorities to ensure the well-being of our personnel and local population."
Pentagon Press Secretary Alyssa Farah said Monday the Department of Defense's top priority is the "safety & wellbeing" of troops, their families, and personnel around the world.
"We're taking every precaution to protect our people from the #COVID19, while safeguarding our national security missions," Farah tweeted.
Last week, the Department of Defense said that three active-duty service members — one in South Korea, one in Europe and one in the U.S. — four family members, one government civilian and one contractor have so far been diagnosed with COVID-19.
Air Force Brig. Gen. Paul Friedrichs, the Joint Staff surgeon said "all are doing well at this point."
All 13 of DOD's clinical labs can run the necessary tests to determine whether a person has COVID-19, the general noted, adding that each base has a plan that is coordinated with local authorities
"The Department of Defense has had plans for dealing with disease outbreaks like this for years," Friedrichs told reporters last week.
About 3,800 cases have been reported in the United States and so far, nearly 70 people have died from coronavirus.
Fox News' Lucas Tomlinson contributed to this report.