The oil tanker 'Devon' prepares to transfer crude oil from Kharg Island oil terminal to India in the Persian Gulf, Iran, on March 23, 2018.

Japan has started the process of importing Iranian oil, which was suspended due to U.S. sanctions, the governor of Iran's central bank said on Monday.

The resumption of oil imports comes after Tokyo was granted a waiver from U.S. sanctions that went into effect in November.

Iran is the fourth-largest oil producer among the members of the Organization of the Petroleum Exporting Countries.

"After China, South Korea, India and Turkey, Japan also started the process of importing Iranian oil," Abdolnaser Hemmati was quoted as saying by the state news agency IRNA.

Iran's oil exports have fallen sharply since U.S. President Donald Trump said in May 2018 the United States would withdraw from a pact curtailing Iran's disputed nuclear program and reimpose sanctions on Tehran.

However, exemptions have been granted to Iran's biggest oil clients — Japan, China, India, South Korea, Taiwan, Italy, Greece and Turkey — which allow them to import some oil for another 180 days.

Iranian oil accounted for 5.3 percent of Japan's total crude imports in 2018.