WASHINGTON — National Security Agency chief Gen. Keith Alexander acknowledged Tuesday that the agency’s fact sheet about its spying program on foreigners could have been “more precisely described” a day after Sen. Mark Udall accused him of being misleading.

NSA’s two-page fact sheet about the 702 program, which gives the agency permission to collect foreigners’ phone and e-mail records, had been circulated to members of Congress and posted on its website.

Udall and Democratic Sen. Ron Wyden of Oregon sent Alexander a letter Monday, obtained by The Denver Post, accusing the agency of “significant” errors in the fact sheet that portrayed Americans’ privacy rights as stronger than they actually are.

The NSA took down the fact sheets from its website Tuesday.

Udall and Wyden were not able to describe what about the program’s description was inaccurate, saying that would divulge classified information.

Alexander’s letter, delivered to both senators Tuesday, said, “I agree that the fact sheet that the National Security Agency posted on its website on 18 June 2013 could have more precisely described the requirements for collection.”

He noted the Patriot Act has limitations on how much information can be collected — including adhering to the Fourth Amendment in the Constitution, which guards against unreasonable search and seizure.

Alexander also noted that the NSA, under this part of the law, cannot intentionally target Americans in or outside the United States.

Coming out of a closed Senate Intelligence Committee hearing Tuesday, Udall said he wants the NSA to do more.

“I appreciate the response; they acknowledge there were inaccuracies,” he said. “I didn’t point them out with great glee; I just want there to be more transparency. I want there to be more clarity. I want there to be informed consent, not blind trust.”

NSA spokeswoman Judith Emmel said the actual words in the Patriot Act are the “best possible representation” of how the government has interpreted the law’s authority.

“Given the intense interest from the media, the public, and Congress, we believe the precision of the source document (the statute) is the best possible representation of applicable authorities,” she said in an e-mailed statement.

Allison Sherry: 202-662-8907, asherry@denverpost.com or twitter.com/allisonsherry