Mexicans living in the United States must send in their ballots on time to have them counted in next month's presidential election, a Mexican Federal Electoral Institute, or IFE, official said.

Some 59,000 Mexicans in 104 countries registered to vote in the July elections, but only 16,000 people have mailed in their ballots, IFE Mexican Voters Abroad Committee chairman Francisco Guerrero told Efe.

"That's 59,000 potential voters and we have received just 16,000 (ballots). The deadline for receiving them expires at 8:00 a.m. on June 30, a day before election day," Guerrero said.

"New York and New Jersey are two of the communities where the number of registered Mexicans has grown significantly. This marks a very important advance with relation to 2006," when the last presidential election took place, the IFE official said.

A total of 2,513 voters registered and have ballots in New York, up by 1,405 voters compared to the 2006 elections, while 857 voters registered in New Jersey for the presidential contest.

California has the most people registered to vote in Mexico's presidential election, with 12,368, followed by Texas, with 7,117; Illinois, with 4,783; and Florida, with 3,036.

Mexicans must have a voter card to cast a ballot and many lack the document.

Enrique Peña Nieto, of the Institutional Revolutionary Party, or PRI, Andres Manuel Lopez Obrador, of the Party of the Democratic Revolution, or PRD, Josefina Vazquez Mota, of the National Action Party, or PAN, and Gabriel Quadri, of the New Alliance Party, are vying to be Mexico's next president.

A poll published last week by the Mexico City daily Reforma showed Peña Nieto drawing the support of 38 percent of likely voters, while Lopez Obrador has the backing of 34 percent of likely voters.

Vazquez Mota, of the governing PAN, is getting the backing of 23 percent of likely voters, while Quadri is drawing just 5 percent support.

Mexico will hold its presidential election on July 1, selecting a successor to President Felipe Calderon.

Nearly 80 million Mexicans will be eligible to vote for a new president, 628 legislators and thousands of other officials in the general elections. EFE