(CNN) Two US military personnel who were assigned to a French aircraft carrier that experienced an outbreak of the coronavirus have tested positive for the virus, according to the US Navy.
"Two of four U.S. Sailors assigned to the French nuclear-powered aircraft carrier FS Charles de Gaulle (R91) tested positive for COVID19 and are receiving excellent host nation medical care at French facilities," Cdr. Kyle Raines a spokesman for the Navy's 6th Fleet told CNN in a statement.
All four US sailors assigned to the ship have been placed into quarantine in France, two US defense officials told CNN.
France's Ministry for the Armed Forces said in a statement Sunday that the nuclear powered aircraft carrier Charles de Gaulle, which has 50 confirmed coronavirus cases on board, arrived in its home port of Toulon on Sunday afternoon and has begun to quarantine personnel who are to be confined to military bases for 14 days.
The presence of US personnel aboard the aircraft carrier has not been previously reported. It is common for US personnel to serve on allied ships in order to bolster interoperability between allied militaries.
The four sailors are part of the US Navy's Personnel Exchange program which the Navy says "fosters strong relationships and enhanced communication with partners and allies."
As part of the program, US personnel are integrated with the French crew in all daily operations, which includes medical care, if needed.
The Charles de Gaulle frequently operates alongside US military forces and played a key role during the air strike campaign against ISIS.
While the carrier has 50 coronavirus cases aboard, the French Armed Forces ministry said last week that it had only tested 66 of the ship's approximately 2,000 personnel.
Coronavirus outbreaks at sea have also proven a challenge for the US Navy, with the nuclear aircraft carrier USS Theodore Roosevelt being sidelined by the pandemic.
On Monday the Navy announced that one sailor who tested positive for the virus had died.
The Navy did not disclose the name of the sailor, who was admitted to the intensive care unit of a US Navy hospital on Thursday. CNN previously reported a sailor from the Roosevelt who tested positive for the virus March 30 was found unresponsive and placed in the intensive care unit during a daily medical check.
The US Navy said Tuesday that 589 members of the ship's roughly 4,800 crew have tested positive for the coronavirus with 93% of the ship's complement having been tested.
More than 4,000 sailors have been moved ashore to Guam where they have been placed into quarantine and isolation.
Four sailors from the ship are currently being treated In a hospital for coronavirus symptoms with one of those sailors having been placed in the Intensive Care Unit "for increased observation due to shortness of breath," according to the Navy.
The Chairman of the Joint Chiefs of Staff Gen. Mark Milley told reporters Tuesday that while the aircraft carrier had been "sidelined" by the pandemic there were no other cases of coronavirus among US warships at sea.
This story has been updated with additional developments Wednesday.