UNITED NATIONS - Western nations are hoping the UN Security Council will be able to vote on Wednesday on a resolution imposing a fourth round of sanctions on Iran over its nuclear program, diplomats said.

Monday's discussions were requested by Turkey and Brazil, two countries that have negotiated a nuclear fuel deal with Iran that they say obviates the need for sanctions.

Ankara and Brasilia had sought a full open meeting of the council to discuss Iran before a vote but eventually agreed there should be further closed-door consultations on Tuesday at ambassadorial level instead. The Western diplomats said they hoped the vote could take place the day after that.

"We'll have consultations tomorrow, another round," US Ambassador Susan Rice told reporters. Asked if the vote would take place this week, she nodded affirmatively.

Turkey, Brazil and Lebanon are not expected to vote for the resolution, but none of them has a veto. Western diplomats are expecting 12 countries, including all five veto-holding permanent council members, to vote for the measure, ensuring it will pass.

The draft sanctions resolution was the product of months of talks between the United States, Britain, France, Germany, China and Russia.

The draft resolution calls for measures against new Iranian banks abroad if a connection to Iran's nuclear or missile programs is suspected, as well as vigilance over transactions with any Iranian bank, including the central bank. It would also expand the UN arms embargo against Tehran.

Diplomats say the exact timing of the vote depends on final agreement on annexes listing members of and firms controlled by Iran's Islamic Revolutionary Guard Corps, entities belonging to the Islamic Republic of Iran Shipping Lines, and other firms and individuals linked to Iran's nuclear and missile programs.

Companies and individuals listed in the annexes will face asset freees and international travel bans.