UNITED NATIONS – America and its European allies yesterday narrowed their differences of approach on Iran’s nuclear program, closing a policy gap with the hope of ratcheting up pressure on the determined mullahs.

American diplomats pored over a European-proposed resolution circulated among board members of the International Atomic Energy Agency in an attempt to make its language even tougher, a Vienna-based Western diplomat told The New York Sun.

The diplomat stressed that the policy gap between Europe and America has narrowed. The two sides, he said, are “closer than we have been.”

At a meeting of foreign ministers in Brussels, top officials from Britain, France, and Germany, which have led the Europe’s diplomacy on Iran, yesterday sounded much tougher on the clerical regime than they have in the past.

“There is the risk of Tehran making a miscalculation,” Germany’s foreign minister, Joschka Fischer, told reporters. “I hope that it sees and understands that. If not, we could be in a serious situation.”

His French counterpart, Michel Barnier, described the proposed resolution for the IAEA as a choice for Tehran. Iran could either “show it can be trusted,” he said, or if concerns remain, “we will have the option of sending the case to the United Nations Security Council.”

The three European foreign ministers, who earlier this year traveled to Tehran, where they signed a pact meant to open Iran’s facilities to IAEA inspection, have in the past resisted the American demand to refer the case to the council, where punitive measures can be imposed.

The proposed European resolution, according to sources in Vienna, calls on Iran to clear all remaining questions on its nuclear program by the next IAEA board meeting in November. Otherwise, the agency’s board would “probably” take further steps, such as sending the case to the council.

American diplomats reportedly demanded a stronger trigger mechanism. They suggested dropping the word “probably.” The Vienna-based diplomat told the Sun that both sides agreed there should be a trigger, and the question is “how strong is the trigger.”

He added that the current resolution, while still falling short of Washington’s preference, takes the Iran issue “one important step further” than previous measures by the 35 members of the IAEA board of governors.

Since the foreign ministers’ trip to Tehran, European and Iranian officials have made opposing statements displaying a gap in interpretation of their signed pact. Most pronounced was Iran’s insistence that it never vowed to quit its attempt to independently enrich uranium, arguing the process could be used for nonmilitary purposes.

That gap seemed to widen yesterday, as Europeans signaled disenchantment with their attempts at diplomatic engagement.

“Iran will have to agree to a complete suspension of enrichment activities,” the Dutch foreign minister, Bernard Bot, demanded in Brussels. The Netherlands currently holds the rotating presidency of the European Union.

Tehran, on the other hand, raised its own disappointment with Europe, insisting on its right to enrich uranium.

The cleric heading the Iranian delegation to the Vienna board meeting, Hossein Mousavian, defined the suspension of enrichment activities as an Iranian “voluntary gesture” yesterday. “Iran should be able to start enrichment activities within a few months but high-level decision makers still have not yet decided about the timing,” Mr. Mousavian said.

The head of the American delegation to the IAEA meeting, John Bolton, made a quick stop in Jerusalem on Sunday on his way to Vienna, where he compared notes with Israeli officials on Iran’s nuclear weapons program.

The chief of Israel’s military intelligence, Aharon Ze’evi-Farkash, told the Israel-Jordan Chamber of Commerce on Sunday that by next year, Tehran could develop its own uranium enrichment capabilities. By 2005, he added, Iran “will have all the means at its disposal to build a bomb.” If it is not stopped, “this may drag the region into a nuclear domino effect,” he warned.