Japan can boost crude oil and natural gas imports from Iran to levels seen before sanctions were stepped up against Tehran, Iranian Oil Minister Bijan Namdar Zangeneh said Sunday.

At a meeting in Tehran with Daishiro Yamagiwa, Japan's senior vice minister of economy, trade and industry, Zangeneh said he would welcome Japanese firms returning to development projects in Iranian oil fields, the Oil Ministry said.

Japan had once depended on Iran for some 30 percent of its oil imports. The share dropped to around 5 percent in recent years as Tokyo joined Western countries in imposing economic sanctions on the Islamic republic over its nuclear development activities.

Iran and six major world powers reached a deal last month to lift the sanctions in return for Tehran curbing its atomic program.

Following the agreement, a senior official with Iran's Oil Ministry told Kyodo News that Japanese companies could return to a development project in Azadegan in southwest Iran, one of the world's largest oil fields. Japan withdrew from the project in 2010.