UNITED NATIONS — Washington’s announcement yesterday that it would launch a new sanctions drive against Sudan exposed a new but distinct difference between President Bush’s impatience with rogue regimes — such as those in Khartoum and Damascus — and the deliberate backroom diplomacy advocated by Secretary-General Ban.

Mr. Ban has been criticized by some U.N. traditionalists as being too close to the Bush administration, but the rift that emerged yesterday demonstrated that the United Nations’s approach to world affairs differs on key issues not only with America, but also with America’s main Security Council allies, Britain and France.

The timing of Mr. Bush’s statement on Sudan yesterday, delivered just as Mr. Ban was seeking to reach a new agreement with President al-Bashir of Sudan to deploy 20,000 U.N.-led troops in Darfur, took the secretary-general by surprise. “He was taken aback,” an aide to Mr. Ban, speaking on condition of anonymity, said.

Similarly, in recent weeks Mr. Ban had often called President Al-Assad of Syria in an attempt to convince him to remove his opposition to a tribunal that would try the alleged assassins of political leaders in Lebanon. Instead, an American-backed Security Council plan to enforce the tribunal, despite Syria’s continuing opposition, will be put to vote as early as today.

“‘Soft power’ issues — the U.N.’s natural turf — have risen to the top of the global agenda,” is how Mr. Ban described the emergence of his favored approach in a Newsweek article published over the weekend.

He cited his consultations with Messrs. Bashir and Assad — known in U.N. corridors as “the Bashir and Bashar show” — as two examples of effective quiet diplomacy.

Mr. Ban had hoped his negotiations with Khartoum, conducted through personal calls on Mr. Bashir and through a special envoy, Jan Eliasson of Sweden, would make sanctions unnecessary. “I have just begun my consultations with the Sudanese government,” Mr. Ban said yesterday, adding that results may be seen as early as next month.

But America and its allies have been unsatisfied by the slow pace of the diplomatic progress while the violence continues in Darfur. “Our patience is running out,” the American ambassador to the United Nations, Zalmay Khalilzad, told reporters. Nevertheless, he added, pressure and persuasive diplomacy “can work together.”

“The United States is not interested in peace in Sudan. They are the biggest spoilers. They spoil everything,” the Sudanese ambassador to the United Nations, Abdalmahmood Abdalhaleem Mohamad, told The New York Sun, adding that negotiations with Messrs. Ban and Eliasson have achieved progress. “Because of the American sanctions, we are now an oil-producing country,” he boasted. “These sanctions are a blessing in disguise.”

“The people of Darfur are crying out for help, and they deserve it,” Mr. Bush said yesterday.

Also yesterday, the Treasury Department announced an asset freeze on two high-ranking members of the Sudanese government and one rebel leader.

All three were indicted by the International Criminal Court on war crime charges related to their roles in the conflict in Darfur.

Mr. Bush said America would launch a drive to impose similar sanctions through the Security Council.

When Mr. Bashir first rebuffed the United Nations’s proposal for a gradual deployment of a strong force in Darfur several months ago, Britain was the first to signal its impatience with Khartoum. As London started to prepare a package of council-mandated sanctions, however, Mr. Ban intervened, saying he would like some time to negotiate an agreed solution.

“We took careful note of what the secretary-general was saying and, as a result of that, we paused,” the British ambassador to the United Nations, Emyr Jones Parry, told the Sun yesterday. “But that pause cannot last much longer.”

It will not be easy to coalesce the Security Council around new sanctions; a group of member countries, led by Russia and China, opposes any international intervention in what they argue are the “internal affairs” of member states.

That group is also expected to withhold support for the resolution on the tribunal in Lebanon. The proposal was officially introduced yesterday by America, France, and Britain, a move designed to force a vote this afternoon.

Concerned that some of its top politicians would be indicted and tried by the international tribunal, Syria has used its proxy politicians in Lebanon to oppose it. Those politicians have successfully blocked a parliamentary vote to ratify the U.N. blueprint.

Several diplomats said yesterday that 10 of the 15 council members were “on board” and would support the proposed resolution to impose the tribunal under Chapter 7 of the U.N. Charter. Russia has said it has “legal issues” with the proposed resolution. It is expected to abstain but not veto the proposal.

American diplomats said as late as last night that they hoped to convince all the members of the council to vote for the tribunal.