The Changsha municipal government has donated 40,000 medical-grade face masks to the US city of Annapolis amid the coronavirus pandemic, AP reported.

Changsha and Annapolis are sister cities.

The donations were first offered to Annapolis city officials in April and the masks arrived this month.

The Capital Gazette reported that one of the boxes featuring American and Chinese flags has a message that reads: "Go, City of Annapolis! Best Wishes from Changsha! True unity inspires people to work as one to overcome adversity."

Another note from Xia Yani, a representative in Changsha's Foreign Affairs Office, accompanied the shipments. "We sincerely wish you and everyone in Annapolis continued good health, and the fortitude to persevere during this challenging period," Xia's note read.

In response to the donations, Annapolis Mayor Gavin Buckley sent Changsha officials a book of photographs of Annapolis.

"International friendships like this bridge divides," Buckley said in a statement. "I'm grateful for the gift of the masks, but I'm even more grateful for what it says about the hopefulness of the human condition."