Foreign Minister Fumio Kishida met with his Iranian counterpart, Mohammad Javad Zarif, Wednesday in Tokyo and urged him to continue making efforts to reach a final agreement with the Western powers on Tehran’s controversial nuclear program.

“Japan welcomes the steady implementation of the Joint Plan of Action (between Iran and the Western powers),” Kishida said during a joint press conference held following talks at the Foreign Ministry’s Iikura guesthouse in Tokyo.

“I believe that there is huge potential in bilateral relations. And to elevate that relationship, solution of the nuclear issue is essential,” Kishida said, adding that Tokyo plans to support Japanese companies’ economic activities with Iran within the framework of a partial lifting of sanctions.

In November, Iran reached a six-month interim deal with six world powers — the U.S., U.K., France China, Russia and Germany — to curb its uranium enrichment in return for partial economic sanction relief.

Iran insists its nuclear program is for peaceful purposes only. But the Western countries have long suspected that Iran is seeking to develop nuclear weapons and its uranium enrichment program is a camouflage for the development.

Tehran and the Western countries began a new round of talks last month, aiming to achieve a fuller deal to place long-term restrictions on Iran’s nuclear program.

But reaching a final agreement may be a difficult task, Zarif said earlier in the day.

“A final agreement is more difficult and easy at the same time. It’s easier because the ice is already broken. . . . It’s more difficult because we need to deal not with a temporary solution but with a more permanent solution. It’s not something that could be reached in one meeting,” Zarif told reporters at the Foreign Correspondent’s Club of Japan.

Zarif also showed his keen interest in Japan’s nuclear power technology.

“Japan is the country with very advanced nuclear energy technology. Very safe nuclear energy technology,” Zarif said. Explaining that Tehran plans to build 19 new nuclear power plants, he said that Japan can take part in their establishment.

“Japan was a good economic partner for Iran. And Iran was a reliable energy partner for Japan,” he said. “I think it is the interest of everybody to resume that partnership. Japan has become absent from the Iranian market for a long time. . . . A lot of possibilities are there. Nuclear cooperation is another possibility,” he said.