Sen. John McCain today defended his assertion that illegal immigrants are to blame for some of the wildfires that have plagued the Southwest, saying that "it's well known this is a significant problem."
The Arizona Republican had raised a storm of controversy with his comments Saturday, when he seemed to blame the currently burning Wallow fire on illegal immigrants, even though the U.S. Forest Service said there was no evidence of that.
McCain said he was not speaking about the Wallow fire in particular, but about a recurring problem.
"This is an old issue," McCain said. "The Forest Service testified in 2006 before Congress that there were fires that were set by illegal immigrants. And the issue has been there ever since ... it's well known this is a significant problem."
Asked specifically for evidence to back up his assertion, McCain continued to cite testimony in Congress by the Forest Service.
"There's evidence that the Forest Service testified before Congress five years ago that there was a significant problem with fires being set by illegal immigrants, particularly down on our border, and there has been ample testimony since," he said. "Our sheriffs down on the border have also testified that that's a significant issue."
Randy Parraz, a civil rights advocate who ran unsuccessfully against McCain as a Democratic candidate in 2010, was quick to deny McCain's accusations, calling them "careless and reckless."
"It's easier to fan the flames of intolerance, especially in Arizona," Parraz said.
Asked about critics like Parraz who accuse him of playing politics during a time when people are losing their homes and are evacuated because of fires, McCain brushed off the issue.
"I regret it if some group or individual wants to insert another issue into this debate," he said. "I'm so proud of the work that's being done and obviously some of the problem has been caused by fires set by illegal immigrants and we ought to address it just as we have requested a couple months ago, six members of the Senate, for an investigation by the Government Accountability Office."
Asked if he believes that his comments Saturday were wrongly characterized, McCain said that "individuals or the groups who criticize this -- they may not be aware that the Forest Service testified in 2006 that this was a serious problem and they described it in detail. It's a problem that is going on for a quite a period of time."
McCain initially made the comments Saturday after touring the Wallow fire, which has consumed more than 515,000 acres in eastern Arizona.
"There is substantial evidence that some of these fires have been caused by people who have crossed our border illegally," McCain said Saturday. "The answer to that part of the problem is to get a secure border."
McCain did clarify that although his comments were made after his visit to the Wallow fire, he was not saying that specific fire was caused by illegal immigrants.
"I certainly wasn't talking about the Wallow fire. That's why I said 'some fires,'" McCain said today. "But there is allegation that the fire called the Monument fire may have been caused by illegal immigrants. But I certainly wasn't talking about the Wallow fire. I was talking about a problem I had just been briefed on by a senior member of the Forest Service."
U.S. Forest Service official Tom Berglund, spokesman for the federal group managing the Wallow fire, said there is no evidence that the Wallow fire was started by illegal immigrants. "Subjects of interest" have been spoken to, but as of now, no suspect has been named, he said.
ABC News' Olivia Katrandjian contributed to this report.