President Vicente Fox underwent three-hour emergency back surgery Wednesday for a herniated disk, leaving two Cabinet members in charge as his country struggles with its position on Iraq.

The successful surgery came at a sensitive time for Mexico, a nonpermanent member of the U.N. Security Council under pressure to back the U.S. stance on Iraq.

On Tuesday, President Bush spoke with Fox by telephone, and Mexican business leaders -- fearing strained ties with the United States -- urged Fox to vote in favor of a resolution setting a March 17 deadline for Iraq to disarm or face war.

Some lawmakers criticized the timing of the surgery, but the president's doctors said it was urgent because the injury was causing him severe pain in his left leg and affecting his ability to walk.

The operation ended at midday Wednesday, and the president planned to talk by telephone later in the day to his Cabinet members about the Iraq situation, spokesman Rodolfo Elizondo said.

El Universal newspaper, quoting unidentified presidential officials, reported Wednesday that the Fox administration was leaning toward a no-vote on Iraq in the Security Council and had rejected the idea of abstaining.

First lady Martha Sahagun and the president's children from a previous marriage were at Mexico City's military hospital for Fox's surgery.

The president was expected to slowly return to work Wednesday -- even though he would remain in the hospital for three to four days after the operation.

Fox's surgery took many Mexicans by surprise. The president had maintained a busy travel schedule until Tuesday, when he canceled all his events to focus on Iraq and then announced his surgery later in the day.

During the surgery, Foreign Secretary Luis Ernesto Derbez was in charge of carrying on Mexico's diplomatic negotiations in the U.N. Security Council, while Interior Secretary Santiago Creel was overseeing national affairs, Elizondo said.

As a non-permanent member of the Security Council, Mexico is among several countries being pressured to take a stand on Iraq.

Fox is trying to find a compromise that will avoid offending voters at home who oppose war and provoking a backlash from the United States, Mexico's largest trading partner and home to millions of Mexican migrants.

Mexico's constitution does not spell out who is in charge when the Mexican president cannot govern, and Fox's surgery once again raised the question of whether the country needed a vice president.

In an interview last week, Fox brushed aside suggestions that a vice presidency should be created, saying his Cabinet was more than qualified to fill in for the president.

Speculating on how the president could have hurt his back, Reforma newspaper published recent photos of Fox carrying heavy bags of supplies for hurricane victims, riding a horse with the first lady, and holding up a baby.