"Developing solidarity and cooperation with African countries is an important cornerstone of China's foreign policy," Xi said in the southwestern city of Chengdu, according to state media.

China has stepped up its engagement with Africa following the abandonment of its strict COVID curbs late last year, inviting heads of state or senior officials from Algeria, the Democratic Republic of Congo, Eritrea, Gabon, Sierra Leone, and Zimbabwe to visit in the past six months.

Xi, speaking to Mauritanian President Mohamed Ould Ghazouani in a bilateral meeting in Chengdu, thanked Mauritania for "always standing firmly with China on issues involving China's core interests".

China and Mauritania also signed a cooperation plan for the Belt and Road Initiative, covering infrastructure, trade, financial cooperation, agriculture, water conservancy and people-to-people exchanges, according to China's state planner.

In a separate meeting in Chengdu, Xi met with Burundi's President Evariste Ndayishimiye and said China is open to strengthen communication and collaboration with Burundi on major international affairs, especially hot-spot issues in Africa.

(Reporting by Joe Cash and Ethan Wang; Editing by Andrew Cawthorne and Philippa Fletcher)