A senior Israeli official told Haffner that Israel "regrets" Swiss Foreign Minister Micheline Calmy-Rey's trip to Tehran this week and views it as an "unfriendly act" toward Israel.

Switzerland is aware of the danger posed by Iran and Israel expects it to join the international effort on this issue, it added.

The United States too criticized the deal earlier Wednesday, with State Department deputy spokesman Tom Casey saying "we don't think that now is the time for people to be investing in Iran, not only in its petroleum or natural gas area, but in any sector of its economy."

The Iranian and Swiss foreign ministers signed the gas agreement on Monday in Tehran. Under the deal, Iran will provide the Swiss firm Elektrizitaets-Gesellschaft Laufenburg 5.5 billion cubic metres of gas per year starting in 2011. The value of the deal was not disclosed. The Israeli Ha'aretz daily reported it is worth an estimated 20 billion euros.

Agencies