The North Carolina man visited by armed EPA agents after sending an email to a controversial agency official says he's not satisfied with the explanations about what he considers an excessive response and that he wants changes to agency policies and procedures.

"This isn't over," Keller said.

He told Fox News.com that Environmental Protection Agency officials have said the agency followed procedures and that the agents acted appropriately during their visit last month. However, Keller is still invited to come to EPA headquarters to discuss the situation.

Keller said he's not willing to come to Washington without knowing what will be discussed.

The incident unfolded after Keller sent an email April 27 to the EPA to try to reach Al Armendariz -- a regional administrator who was under fire for a YouTube video post days earlier in which he said his enforcement strategy was to "crucify" executives from big oil and gas companies.

The letter to an EPA external affairs director read "Do you have Mr. Armendariz's contact information so we can say hello? - Regards- Larry Keller."

Keller said he was just asking as a taxpayer and denies being part of the Tea Party, though he acknowledges supporting the movement's calls to defund the agency in part because it has outreached its intended mission.

"We are a customer of them," he said.

Armendariz, whose region included oil-rich Texas, New Mexico, Oklahoma, Arkansas and Louisiana, resigned April 29 for the comments, made in 2010.

The agents visited Keller's home in Ashville, N.C. on May 2 to ask him about the email, which after some misunderstanding Keller acknowledged sending. He said after a brief, tense discussion about whether the missive might seem suspicious, the agents, who were escorted by the local police, left despite Keller ask them to stay to his wife could witness their visit.

"The charter of the EPA is to protect the environment and public, not to act as a quasi federal police department," Keller said Saturday.

Keller appears to have some support in Washington. GOP Sen. Richard Burr's office has agreed to look into the matter.

The North Carolina senator could not be reached this weekend, but a staffer told the Carolina Journal.com that Burr's office has initiated an inquiry with the EPA and that the senator "intends to pursue this matter vigorously."

A regional EPA official told Keller the agency was following up on his email, considering its timing and the number of threats against Armendariz.

"I want a change of policy and procedure," Keller said. "They've got big problems."