Posted: Tuesday, January 21, 2014 6:54 pm | Updated: 10:03 pm, Tue Jan 21, 2014.

Associated Press |

U.S. Homeland Security Secretary Jeh Johnson said Tuesday on a visit to the Texas-Mexico border that the surge of immigrants from countries other than Mexico crossing the border illegally presents challenges to the department.

"What has been brought home to me today is that we need to continually monitor trends in border crossings," Johnson said at the Anzalduas International Bridge. "We need to continually try to stay ahead of the game when it comes to trends, emerging trends."

While arrests of Mexican citizens remained nearly unchanged last year, arrests of immigrants from other countries, including Guatemala, El Salvador and Honduras, increased 55 percent, according to data released by U.S. Customs and Border Protection on Friday.

Johnson, who won Senate confirmation to lead the Department of Homeland Security in December, did not elaborate on those challenges, but in the past year the growing flow of immigrants especially from Central America have at times overwhelmed Border Patrol stations in South Texas creating backups in processing and other logistical challenges. The Border Patrol's Rio Grande Valley sector, which spans Texas' southernmost tip, has become the busiest illegal crossing segment of the Southwest border. It received additional personnel and technology last year.

"We need to continually evaluate whether they need more resources," Johnson said.

The Border Patrol made 420,789 arrests in the fiscal year that ended in September. That is a 16 percent increase from the previous year but still 42 percent below 2008. Agents in Texas made 235,567 of those arrests.

In the Rio Grande Valley sector, immigrants from countries other than Mexico made up the majority of the arrests.

Johnson said he had spent Tuesday touring Homeland Security operations in the region, including travelling with agents patrolling the Rio Grande and visiting a detention center.

In addition to border security, Johnson said it was important to facilitate trade and commerce.

He met with two Texas congressmen and several local officials who for years have argued that the area's ports of entry need more customs officers to keep traffic flowing.

The spending bill signed by President Barack Obama on Friday included funding for 2,000 more customs officers to police the nation's 329 ports of entry. There are already more than 21,000 customs officers.

Before meeting with Johnson on Tuesday, U.S. Rep. Henry Cuellar, D-Laredo, said DHS had a staffing model that would be used to determine where the new officers are placed. Last year, when Cuellar was discussing funding for about 1,800 officers, the agency told him he could expect to see about 200 of them come to South Texas ports of entry from Laredo to Brownsville. He said he expected to receive an updated estimate soon.

"We have to make sure we get our fair share," Cuellar said.

Johnson was scheduled to make a similar visit to Tucson, Ariz., on Wednesday.