Berlin: German Chancellor Angela Merkel said a UN report that Iran had worked on an atomic weapon design was "alarming" but sanctions had not been fully exhausted as a means of pressuring Tehran, and Germany would consider a tougher round of measures.
In an interview with the Leipziger Volkszeitung published on Saturday, Merkel said opposition to fresh sanctions against Tehran over its nuclear programme by some countries was "regrettable".
Russia and China have declared their opposition, limiting the chances of pushing through another UN Security Council package.
"I think the methods we can use to force Iran to be more transparent have not been fully exhausted. Sanctions are first in line here. These sanctions should be as broad as possible," Merkel said.
Iran had clearly "not put all its cards on the table", and she urged the country to act with transparency.
United States Secretary of State Hillary Clinton said on Friday Washington was consulting allies on further steps to pressure Iran, but she stopped short of specifying actions under consideration.
Earlier this week, the International Atomic Energy Agency concluded that Iran had worked on developing an atomic bomb design and may still be conducting such research.