Updated

Border states are looking to take matters into their own hands, boosting law enforcement to patrol for illegal immigrants while their pleas for federal assistance go unmet in the wake of the murder of a prominent Arizona rancher.

Local authorities suspect Robert Krentz, found dead on his cattle ranch Saturday night, was killed by an illegal immigrant who fled back across the border into Mexico.

Gov. Jan Brewer told Fox News on Wednesday that after repeatedly calling on the federal government to send in 250 National Guard troops, she hasn't ruled out making the call herself.

"I can, and I haven't ruled that out," she said. Brewer has also offered state law enforcement help to the county where the killing occurred, while the Arizona Department of Public Safety and Department of Corrections are helping to coordinate the search for the suspect, according to her office.

But Brewer stressed that Arizona cannot afford to sustain or maintain the additional National Guard presence. She said border security is a federal responsibility -- and she said the administration simply is not stepping up.

"We've been talking to the federal government in regards to our borders and it just seems that they don't want to participate in any shape, form or manner," she said. "They just don't even respond."

New Mexico Gov. Bill Richardson also announced Tuesday that he's increasing law enforcement along his state's border with Mexico while the investigation is underway. His office said New Mexico state police and local sheriff's offices have stepped up patrols all along the border -- and that the U.S. Border Patrol has increased its presence as well.

But officials including Brewer, Sen. John McCain, R-Ariz., and several U.S. representatives out of New Mexico have called for a much bigger federal presence on the border -- a combination of National Guard and Border Patrol -- in the aftermath of Krentz's murder.

"The federal government's responsibility is the border. It's a federal responsibility, not a state responsibility," McCain said. "So the federal government should be the ones that pick up the tab for sending the guard to the border."

Matthew Chandler, spokesman for the Department of Homeland Security, told FoxNews.com in a written statement that the department "will respond directly to the members of Congress" who are making the requests.

Homeland Security Secretary Janet Napolitano, formerly the governor of Arizona, "shares these members' concern about the safety of U.S. border communities and is committed to working with our state, local, tribal, and Mexican law enforcement partners to combat threats from violent cartels on both sides of the border," he said.

Napolitano, since taking over Homeland Security, has increased the number of intelligence analysts, special agents and canine teams along the border. But critics say Border Patrol teams are ineffective and that hundreds of miles of fencing are either missing or not high or sturdy enough to keep out illegal immigrants.

The Krentz killing has served as a rallying cry for those who have long called on the federal government to overhaul its approach to the southwestern border. The Krentz family had personally been airing its concerns about illegal immigrants to federal authorities for years.

Though Secretary of State Hillary Clinton just returned from leading a delegation to Mexico City to discuss the offensive against the drug trade and related border violence, the State Department had no comment on the Krentz killing.

The White House could not be reached for comment.

A few days before the murder, Texas Gov. Rick Perry deployed helicopters to the border to patrol and wrote to Napolitano calling for the federal government to do more to stem border violence.

In a letter to Napolitano, Perry asked for the department to use a new drone for surveillance along the Texas-Mexico border -- he complained that the handful of drones currently in operation are split between North Dakota and Arizona.