Two members of Congress on Sunday accused the National Security Agency of keeping Congress in the dark regarding its domestic surveillance programs.

When “Fox News Sunday” asked Sen. Bob Corker, R-Tenn., if he thought Congress was adequately briefed on government surveillance programs within the United States, he said, “Absolutely not.”

“Look, I appreciate efforts to keep Americans secure. But at the same time this is in front of us, we are not in front of it,” he said. “The American people want to know that those of us who are elected … understand fully what’s happening here. I don’t think we do.”

While Corker isn’t on the Senate Select Committee on Intelligence, he said he suspects members of the panel “don’t fully understand the gambit of things that are taking place.”

Corker wrote to President Obama last week asking that NSA Director Keith Alexander brief Congress when it returns to Washington next month regarding the agency’s domestic spying programs.

“It’s our responsibility to know those things, to ensure they’re in balance, and I hope as soon as we get back [from summer break] there will be a full briefing from top to bottom,” he said.

Rep. Eliot Engel, D-N.Y., also said on “Fox News Sunday” he’s troubled by reports suggesting that lawmakers “really haven’t been told the truth” regarding surveillance programs.

“I do think Congress needs to revisit this issue and come up with a plan,” he said. “We don’t feel that we’re being told everything, and that’s not really the way things should work.”

The pair’s complaints come as the German magazine Der Spiegel reported Sunday that the NSA secretly monitored the United Nations' internal video conferencing system by decrypting it last year.

The weekly publication said that documents it obtained from American leaker Edward Snowden show the NSA decoded the system at the U.N.’s headquarters in New York last summer.

Quoting leaked NSA documents, the article said the decryption “dramatically increased the data from video phone conferences and the ability to decode the data traffic.”

In three weeks, Der Spiegel said, the NSA increased the number of decrypted communications at the U.N. from 12 to 458.

A wire service report was used for this article.