Japan will use its place on the United Nations Security Council to push for an African seat on the top world body, Prime Minister Fumio Kishida said Sunday.

"Japan reiterates its determination to redress the historical injustice against Africa of not being represented through a permanent membership on the Security Council," Kishida told the Tokyo International Conference on African Development in Tunis.

"In order for the UN to work effectively for peace and stability there is an urgent need to strengthen the UN as a whole through Security Council reform," he said.

The UN faces "a moment of truth," he added.

Japan was among five countries elected in June to hold a non-permanent seat on the UN Security Council for 2023 and 2024.

Kishida, speaking over live video from Tokyo after testing positive for Covid-19 days earlier, reiterated a pledge announced on Saturday to invest some $30 billion in Africa over the next three years.

He also announced that Japan would appoint a special envoy to the Horn of Africa, where a long drought has prompted the UN's weather agency to warn this week of an "unprecedented humanitarian catastrophe".

Kishida said Japan would pump $8.3 million into the troubled but gold-rich Liptako-Gourma tri-borders area between Mali, Niger and Burkina Faso that has been ravaged by jihadist attacks in recent years.

The aid will aim to "develop good cooperation between residents and local authorities" and help improve administrative services for the area's five million residents, he said.

The Japanese premier also promised aid to train police officers and support "fair and transparent" elections across the continent, pledging Japan's support for the rule of law in Africa.

The UN Security Council is made up of 15 members, five of whom are permanent and have veto-wielding power: the United States, Russia, China, France and Britain.

The other ten positions are filled by other countries for two-year stints, five of which are announced each year.