Samoa signed a bilateral agreement with China on Saturday promising closer cooperation as Beijing's foreign minister continues a tour of the South Pacific that has raised concerns among Western allies, AFP reported.

The details of the agreement are unclear as it was signed in the middle of a Chinese delegation's eight-country trip, but a previously leaked draft agreement sent to several Pacific countries outlined plans to expand security and economic cooperation.

The mission has prompted Western leaders to urge regional partners to push back any attempt by China to expand its security footprint in the region.

A press release from the Samoan government confirmed that Chinese Foreign Minister Wang Yi and Samoan Prime Minister Fiame Naomi Mataafa met and discussed climate change, the pandemic, peace and security.

Local media were invited to witness the signing of the agreement, but no questions were asked.