Mexican President Vicente Fox is taking his five-year battle for immigration reform to the front lines with a trip this week to California, Utah and Washington.

But some say the visit may do more harm than good.

Fox wants the U.S. Congress to approve a guest worker program and a path for citizenship for some of the 6 million undocumented Mexicans in the country.

But his visit could be seen as meddling in U.S. politics and strengthen support for hard-liners who want to tighten immigration laws.

"This trip has all the makings of a boomerang," said George Grayson, a Mexico expert at the College of William and Mary. "It is going to be virtually impossible to be critical enough to keep his political support back home, while not looking like he is interfering in U.S. affairs."

During the five-day trip which starts Tuesday in Utah, Fox plans to meet with state governors and legislators, business leaders and Mexican migrants.

"The Mexican government wants to do its part to promote an immigration reform," Fox's spokesman Ruben Aguilar said Monday. "Meeting with the Mexican community in these states, this Mexican government wants to show its total support for the defense of the their labor and human rights."

CountryWatch: Mexico

Fox will meet California Gov. Arnold Schwarzenegger and will talk with Los Angeles Mayor Antonio Villaraigosa. He also plans to get his cowboy boots dirty traipsing around a farm where Mexicans work in Washington state.

Immigration and border security have deeply divided the United States and provoked huge migrant marches in Los Angeles, Dallas, Texas, and other U.S. cities.

Last week, Bush announced plans to send 6,000 National Guard troops to the border. Days later, the U.S. Senate approved building 370 miles of triple-layer fencing.

The Mexican government expressed concerns about both measures, saying they would not control undocumented migration.

But opposition politicians criticized Fox for not vigorously protesting the border security plans, which many Mexicans view as a slap in the face.

Fox's government, however, appears to be holding back, with the hope that the U.S. Congress will push through a comprehensive immigration reform package that will help legalize Mexicans in the U.S. and set up a guest-worker program.

The journey comes at a politically sensitive time south of the border with a presidential election six weeks off. Felipe Calderon from Fox's conservative National Action Party is in a tight race with leftist Andres Manuel Lopez Obrador, of the Democratic Revolution Party. Mexican law bars Fox from seeking re-election.

Fox has made a migration accord with the United States a cornerstone of his foreign policy since he took office in 2000. In 2001, he brought the issue to Washington, touting it before a joint session of U.S. Congress.