UNITED NATIONS – The Security Council is expected to vote on an American-backed resolution to impose the next round of sanctions on Iran as early as Wednesday, but two countries bent on enabling Iran, Brazil and Turkey, are making a last-ditch effort to delay the vote.

Ambassadors of the two countries called for a hasty Security Council consultation earlier today to try to schedule a public debate — a procedure that remotely resembles the Congressional filibuster — before any vote could takes place.

“We don’t want to be obstructionist, we don’t to delay anything, we just want to have a political debate,” Brazil’s ambassador here, Maria Viotti, told me after today’s session. Until now “there has been only a technical debate on the resolution,” she said. “We think that this issue is a broader issue, a political issue.”

Several Western envoys said they expected the vote to take place Wednesday, or “this week,” as the American ambassador here, Susan Rice, said.

Not so fast, retorted Ms. Viotti. “We don’t want to discuss the [sanctions] resolution, we want to discuss the issue in a broader context,” she said.

Nevertheless, the latest maneuvering represents an admission of sort by the two countries that a new round of Iran sanctions is inevitable.

The five permanent council members and Germany agreed on a much-compromised American sanctions package last month. They finally coalesced around the new package only after President Lula and Prime Minister Erdogan embraced President Ahmadinejad a day earlier, announcing a diplomatic solution that was supposed to stop the sanctions drive at Turtle Bay.

Since then, the ambassadors representing the two countries here insisted that they were not even “engaged” with other council members on the sanctions talks. Ms. Valiotti repeated that trope to me as late as last week. But today, when I asked if they’re now finally engaged in council discussions, she said, “We will be, tomorrow.”

The last-ditch efforts show how far the Obama administration has strayed from its earlier intent to impose “crippling sanctions” on Iran. After a whole year in an attempt to talk the Tehran mullahs out of building atomic bombs, Washington circulated its original ideas for sanctions to council members back in February. But as winter turned to spring, and soon to summer, and as resistance from China and Russia persisted in backroom consultations, the original sanctions package was much diluted.

Most ominously, Russia was exempted from a proposed embargo on relevant weapons. Under the current proposed sanctions package, Moscow would be able to sell Iran dozens of S-300 surface-to-air missiles, which can hamper any plan to conduct a military assault on Iran’s nuclear facilities from above.

Just as worrisome, after three sanctions resolutions that the Security Council has imposed on Iran during President Bush’s tenure at the White House, the current proposed round is expected, for the first time, to be passed by a truly divided council. Ankara, Brasilia, and Beirut have yet to declare whether they would vote against the resolution or merely abstain, but they indicate that they do not intend to support the sanctions. In the aftermath of the council resolution’s passage, several Iran-enablers beyond Turkey, Brazil, and Lebanon could yet declare that the resolution does not apply to them.

Mr. Obama, who came in promising to “heal” the rift that his “unilateral” predecessor opened with the rest of the world, will end up with pronounced divisions at the most prominent international body, over the most important foreign policy matter of his presidency to date. The comparison will make Mr. Bush seem like a world “uniter.”