In a news conference with foreign journalists, Calderon said he will try to convince lawmakers that the accord is in both countries' interests.

"We will work intensely over the next two years to arrive at a concrete agreement with the Bush administration," he said.

Outgoing President Vicente Fox spent his six-year term unsuccessfully pushing the United States for an immigration accord. Calderon has said the September 11 attacks held back Fox.

On Thursday, Calderon said he would work to capitalize on the attention the immigration issue is receiving in the United States and persuade Washington to take action.

Also Thursday, Fox spokesman Ruben Aguilar said the president is inviting Mexico's main leftist party to negotiate a solution to the nation's divisive political crisis and work toward unifying the country.

Aguilar said the president is contacting all five former presidential candidates and their parties and asking them to meet with him.

Fox, who under Mexican law can serve only a single six-year term, leaves office December 1.

"Talks always help the political activity," Aguilar told a news conference.

Runner-up Andres Manuel Lopez Obrador has refused to recognize Calderon's victory, and he planned an Independence Day convention that may name him as the nation's alternative leader.

He has said fraud is responsible for Calderon's slim lead.

In a largely symbolic ceremony late Wednesday, the Federal Electoral Tribunal's seven magistrates also gave Calderon a document recognizing him as the winner of the bitterly disputed July 2 election by a margin of fewer than 234,000 votes out of 42 million cast.

Calderon, a 44-year-old lawyer and member of Fox's National Action Party, pledged once again to govern for all Mexicans -- an olive branch to the millions who didn't vote for him.

Outside the court, Lopez Obrador supporters spit at one judge as she arrived at the ceremony and threw eggs at a former federal official who was a member of Calderon's campaign. Calderon arrived early, entering the court through a back door away from the protesters. Dozens of federal police stood guard outside, and no injuries were reported.

During his nightly rally at a protest camp in Mexico City's main square, Lopez Obrador claimed Wednesday he already had 210,000 people signed up for a "great people's assembly ... to decide the destiny of our nation."

He said he hopes more than 1 million will attend what he's calling the National Democratic Convention on September 16, Mexico's Independence Day. In the past, he has said the convention will choose between naming him as "chief" or "coordinator of resistance" or "legitimate president."