Japanese architect Ban Shigeru says he will cooperate in building a surgical ward belonging to a hospital in the western Ukrainian city of Lviv to provide treatment to people who have been injured in Russia's invasion of the country.

Lviv Mayor Andriy Sadovyy and the world-renowned architect unveiled the plan in a news conference on Tuesday in Tokyo.

They said they aim to start the construction of the hospital ward using Ukrainian timber next summer. They said they hope to raise about 80 million dollars for construction costs, and are counting on support from the international community.

The mayor reportedly asked Ban to design the building.

Ban stressed that "We need to build immediately, even before the war is ended."

Sadovyy said Ukraine is fighting to protect its independence and needs Japan's experience, indicating his wish to apply Japan's knowledge and technologies to improve medical care.

About 150,000 internally displaced people are said to be living in Lviv after they fled Russian attacks in the eastern and southern parts of Ukraine. The city has a population of about 700,000.

More than 15,000 injured people have reportedly received treatment in the city.