TOKYO—Israeli Deputy Prime Minister Ehud Barak on Saturday during a visit to Japan called for an "urgent" tightening of sanctions targeting Iran´s oil exports and access to global financial clearing houses, urging his Japanese hosts to put more pressure on Tehran to dissuade it from developing nuclear weapons.

"We have to increase the pace of imposing sanctions" on Iran´s oil, central bank and access to international credit, Mr. Barak said at a press conference in Tokyo. "This should be done determinedly and in a conclusive manner and urgently."

That came after an announcement Friday by the Belgium-based Society for Worldwide International Financial

Telecommunication, or Swift, to prepare to stop blacklisted Iranian banks from accessing its financial communications and clearing systems, a move that could seriously impede Iran´s ability to pay for imports and receive payment for exports.

The Israeli deputy prime minister, who also serves as defense minister, made his remarks to reporters during a five-day visit to Japan that included meetings with senior Japanese officials, including Prime Minister Yoshihiko Noda, Foreign Minister Koichiro Gemba and Defense Minister Naoki Tanaka. It is the first visit to Japan by an Israeli defense minister in 18 years.

Prime Minister Noda told Mr. Barak on Wednesday that Japan would reduce its imports of Iranian oil, but Foreign Minister Gemba warned the Israeli deputy prime minister that using military force against Iran may be counterproductive, Kyodo News reported.

Mr. Barak would not comment directly on his meetings with Japanese officials, but his message was clear as he reiterated Israeli´s position of not ruling out a military option if sanctions fail to persuade Iran to abandon a suspected nuclear weapons development program. "When we say that we will not leave any option off the table, we mean it," he said.

Iranian oil makes up only about 10 percent of Japan´s total imports, but 80% of Japanese oil imports pass through the Strait of Hormuz, which Tehran has threatened to close.

Mr. Barak also said that embattled Syrian President Bashar al-Assad and his regime may be toppled from power in a matter of "weeks" amid growing protests, noting that he does not expect the current government in Syria would survive into 2013. Write to Chester Dawson at chester.dawson@wsj.com (Copyright © Dow Jones & Company, Inc.) 02/18/12)