The new U.S. Ambassador to Mexico, Tony Garza, has arrived at his post in Mexico City promising to focus attention on such bilateral issues as trade, the environment, the fight against drug smuggling and immigration. Mexican officials want to put the immigration issue at the top of the agenda.

In a brief statement on arrival at the Mexico City International airport, Mr. Garza said the United States and Mexico face some great challenges and great opportunities. He expressed confidence that the two nations can work together in a positive way to take advantage of the opportunities.

Mr. Garza arrived here in Mexico just days before an annual binational meeting in which Secretary of State Colin Powell will participate. Mexican Foreign Minister Jorge Castaneda, who will host the event at his Secretariat building next Monday and Tuesday, has said his country is still pursuing an immigration accord with the United States that would give legal status to millions of Mexican workers north of the border.

The two countries seemed close to achieving such an accord during a visit to Washington by Mexican President Vicente Fox in September, 2001. But only a few days after that visit, on September 11, terrorists attacked New York and Washington and relations with Mexico were no longer a top priority for the Bush administration.

However, in a recent interview with Mexico's Reforma newspaper, Tony Garza said the issue is not forgotten. He said the United States may be able to offer legalized residency to about 15 percent of the undocumented Mexican workers currently living there. This falls short of what the Fox government has sought, but it might be a first step towards a more comprehensive package at a later date.

Among other topics on the agenda for the binational meeting next week are trade, border security and water. Last month, the United States accused Mexico of failing to comply with a treaty that regulates use of water from the Rio Grande river, which forms the border between the two nations for more than half of its length.