Leaders of the European Union and Japan have launched an alliance aimed at boosting economic cooperation, defending free trade and countering unfair trade practices as the two sides face growing challenges from the United States and China.

Japan's exports to the US are to face a 15% baseline tariff and the EU is more confident a similar rate can be agreed before 1 August.

The European Union and Japan will work more closely to counter economic coercion and address unfair trade practices, European Commission President Ursula von der Leyen told reporters on Wednesday.