Visiting Iranian President Hassan Rouhani met Prime Minister Shinzo Abe on Friday in Tokyo, urging Japan to pursue stronger relations and to assist the Middle Eastern country, which is suffering under the weight of severe U.S.-imposed economic sanctions.

Rouhani is in Japan for a two-day visit after attending an international conference of Muslim leaders in Malaysia.

“This bilateral relationship has a long history and is very important for our country,” Rouhani told Abe at the outset of the meeting at the Prime Minister’s Office in Tokyo.

“I hope new concrete steps to promote the bilateral relationship” will be taken, he said, speaking through a translator.

Facing reporters with Rouhani, Abe welcomed the visit, pointing out it marks the 90th anniversary of the start of diplomatic relations between the two countries.

Abe at the same time said that Tokyo hopes that Tehran will “fully implement” obligations under a 2015 nuclear deal that was designed to freeze Iran’s nuclear development program.

Rouhani is the first Iranian president to visit Japan since 2000.

Iranian officials have expressed hope that Japan will resume buying Iranian crude oil by defying or bypassing U.S.-imposed sanctions, which have led to severe inflation, damaging the livelihoods of Iranians.

But according to a senior Japanese official who briefed reporters later in the day, Rouhani didn’t bring up the topic during the meeting with Abe.

Senior Japanese officials have said Tokyo won’t be able to satisfy Tehran’s wishes as Washington has maintained a tough stance against anyone who defies the sanctions.

“No, we can’t do it when U.S. sanctions are in place,” an official said to reporters, speaking on condition of anonymity.

“As far as we know, no (Japanese) oil wholesalers have bought crude oil from Iran since May this year,” the official added.

In May, the U.S. ended the moratorium of sanctions for Japan, threatening to slap fines or restrict access to the American market if any firms — including Japanese ones — imported oil from Iran.

Last year, U.S. President Donald Trump unilaterally withdrew from the 2015 deal with world powers to freeze Tehran’s nuclear program in an apparent bid to erase a legacy left by his predecessor, Barack Obama. Iran maintains its nuclear program is for peaceful purposes.

In response, Iran in May started reducing its commitment to the deal, escalating such moves every two months.

Iranian officials have suggested that Tehran may place restrictions on inspections by the International Atomic Energy Agency early next month as a fifth step to reduce its commitment to the nuclear pact.

According to the Japanese official who briefed reporters, Abe also expressed “grave concerns” during Friday’s meeting over Iran’s threat to reduce its commitment and urged Rouhani to stop any actions that would further undermine the nuclear deal.

In response, Rouhani himself emphasized the importance of the nuclear deal and at the same time elaborated on “Iran’s own position” on the issue. The Japanese official declined to further explain Rouhani’s argument.

During the meeting Abe also explained his plan to dispatch a destroyer and anti-submarine patrol aircraft to the sea off Oman and Yemen. The plan is due to be officially endorsed by the Cabinet later this month.

In response, Rouhani said he appreciates “the high transparency” of Abe’s explanation and understands Japan’s intention to secure safety of navigation in the region by dispatching the Self-Defense Forces, the senior Japanese official said.

Washington had urged Tokyo to deploy an SDF unit as part of a U.S.-led coalition that is aimed at keeping Iranian military forces in check. Abe has instead decided to send an “independent” SDF force to gather information on security in the Middle East in an apparent bid to maintain Japan’s reputation as a politically neutral presence in the region.

Tehran proposed that Rouhani visit following Abe’s trip to Tehran in June, which was the first visit by a Japanese prime minister in 41 years.