U.S. Secretary of State Hillary Clinton warned on Sunday of Iran “stunts” ahead of a visit to Latin America where regional powerhouse Brazil opposes the U.S. drive for new U.N. sanctions over Tehran’s nuclear program.

Clinton said she fully expected Iran to “pull some stunt” in the coming days to try to divert pressure for sanctions, but predicted this would fail.

“I think we’ll see something coming up in the next 24 to 48 hours,” Clinton told reporters aboard her plane before departing. “I don’t think anybody should be surprised if they try to divert attention once again from the unity within the Security Council … but we have the votes,” she said.

Clinton’s trip takes her to Peru for a meeting of the Organization of American States (OAS), followed by stops in Ecuador, Colombia and Barbados.

The Obama administration has battled perceptions in Latin America that early vows of close cooperation have failed to materialize along with pledges to liberalize treatment of Cuba and to review immigration laws.

“The expectations in the region ran way ahead of reality and there is a certain disappointment and cynicism that has set it,” said Eric Farnsworth, vice president of the Washington, D.C.-based Council of the Americas.

“Some of these things are devilishly difficult and it is not going to happen overnight,” he said. “The secretary is going to try to put this in a broader context.”

U.S.-Brazil ties have been strained by possible new U.N. sanctions on Tehran, which Washington has said it hopes to put to a U.N. Security Council vote this week. Brazil, along with Turkey, wants more time for diplomacy.

Both sides say the Iran issue is only one part of a broad and growing U.S.-Brazil relationship. But the dispute has set the United States publicly at odds with Latin America’s fastest rising power as it stakes out a spot on the world stage.

Despite the Latin America focus, Iran looks certain to push its way onto Clinton’s agenda.

The United States is pushing hard for new U.N. sanctions, saying Iran’s violations of its nuclear obligations leave no doubt it seeks atomic weapons — a charge Tehran denies.

But Brazil and Turkey, both now nonpermanent members of the council, have sought to revive a proposed atomic fuel deal for Tehran, declaring that sanctions should be avoided.

The United States has built a fragile consensus with the four other veto-wielding permanent Security Council members, Britain, France, Russia and China, and says the fuel deal idea fails to address core concerns over Iran’s nuclear ambitions.

But the Security Council showdown with two of the developing world’s most influential countries over Iran could underscore the limits of U.S. influence over even friendly emerging powers like Brazil.

“The United States has still not factored in the inescapable conclusion that Brazil today is on an irrevocable path toward independent foreign policy,” said Larry Birns, director of the Council on Hemispheric Affairs in Washington.

(Read More: Reuters)