He made the remarks in a phone conversation with Namibian President Hage Geingob.
The coronavirus disease caught the world by surprise and has posed a major test of governance capacity to all governments across the world, Xi said.
The Chinese government always puts people in the first place and gives top priority to people's safety and health, he said, adding that thanks to more than two months of arduous efforts, China's epidemic prevention and control situation has been continuously improving.
With enormous efforts and sacrifices, the Chinese people have bolstered confidence, bought time and accumulated experience for other countries' epidemic prevention and control, said Xi.
In the face of this global public health crisis, only through solidarity and cooperation can the international community overcome the pandemic, stressed the president.
Xi recalled that at the extraordinary leaders' summit of the Group of 20 major economies a few days ago, he urged the international community to step up action, effectively carry out collective prevention and control, resolutely contain the spread of the epidemic, and particularly work together to help developing countries with weak public health systems to enhance preparedness and response.
During the most difficult period of China's fight against COVID-19, African countries provided China with valuable support, which will be engraved in the hearts of the Chinese people, Xi said.
Expressing deep concern about the current COVID-19 situation in Africa, he said China has overcome difficulties to actively assist the African Union and African countries with anti-epidemic supplies, and organize video conferences of medical experts to share experience.
Meanwhile, Chinese enterprises and non-governmental organizations have also extended a helping hand to African countries, he added, pointing out that all these are true manifestations of the China-Africa community with a shared future.
China, Xi said, will continue to share experience on epidemic prevention and control with African countries, and work with them to enhance cooperation in health care and win the final victory over the pandemic.
He added that he is confident that the friendship between China and African countries, including Namibia, will grow deeper in the joint fight against the epidemic.
Noting that this year marks the 30th anniversary of bilateral diplomatic ties, he said China stands ready to work with Namibia to seize the opportunity to maintain mutual understanding and support, strengthen practical cooperation and lift China-Namibia and China-Africa relations to new levels.
For his part, Geingob said Xi has led the Chinese people in waging an effective fight against the pandemic, which has demonstrated outstanding leadership and been highly appreciated by countries around the world, including those from Africa.
With the attention and care given by the Chinese government, more than 500 Namibian students have been safe and sound in China, Geingob said.
Noting that China is the best friend of Namibia and of Africa, he said he deeply appreciates the Asian country's timely and precious assistance and support to African countries in their fight against the disease.
Namibia and China enjoy a close and friendly relationship, with bilateral cooperation continuously expanding, he said, adding that the Namibian side is willing to strengthen governmental and inter-party exchanges and cooperation with the Chinese side, learn from China's successful experience in poverty alleviation, and continue to advance the Namibia-China comprehensive strategic partnership of cooperation.