Earlier, the United States embassy in Canberra, the Australian capital, had said the Solomon Islands had notified it of a moratorium on navy vessels entering its ports.
“On Aug 29, the United States received formal notification from the government of Solomon Islands regarding a moratorium on all naval visits, pending updates in protocol procedures,” the embassy said in a statement.
The Mercy had arrived before the moratorium, the embassy said, adding that it was monitoring the situation.
The Mercy’s humanitarian mission, together with personnel from Australia and Japan, will include community health outreach, engineering projects and discussions on disaster relief.
The Solomon Islands has had a tense relationship with the United States and its allies since striking a security pact with China this year.
The Oliver Henry was on patrol for illegal fishing in the South Pacific for a regional fisheries agency at the time it sought entry to refuel at Honiara, the Solomon Islands’ capital.
On Monday, a US State Department spokesperson called the lack of clearance for the Oliver Henry “regrettable”, saying that the United States was pleased the Mercy had received clearance.
Separately, White House National Security Council spokesman John Kirby said it was regrettable that “we’ve seen the Chinese try to bully and coerce nations throughout the Indo-Pacific to do their bidding and to serve what they believe their selfish national security interests are, rather than the broader interests of a free and open Indo-Pacific”.