WASHINGTON (Reuters) - There have been no credible threats against the United States for the anniversary of the September 11, 2001, attacks next week, U.S. Attorney General Eric Holder said on Wednesday.

"We don't have any credible, specific allegations of activity or threats of any kind of activity on September 11," Holder told reporters. "We are being vigilant with regard to what is out there. We are prepared to respond to anything that we see."

The Justice Department, FBI and other investigative agencies were prepared to respond to any threats that do emerge ahead of the anniversary, Holder said, adding that Americans should report any suspicious activity to local authorities.

He said there will be a visible increase in the presence of law enforcement authorities leading up to Sunday's anniversary.

"But as I said we have no specific credible allegations that are of concern to us now, but the threat is constantly there," Holder said.

(Reporting by Jeremy Pelofsky, editing by Eric Beech and Bill Trott)