President Obama today assured German Chancellor Angela Merkel that the United States "is not monitoring and will not monitor" her communications, White House Press Secretary Jay Carney told reporters.

Carney, however, said nothing in the past tense, leaving open the possibility that the U.S. could have monitored her communications in the past. In follow-ups, the White House would not specifically deny that the chancellor's communications may have been monitored at some point.

"The United States greatly values our close cooperation with Germany on a broad range of shared security challenges. As the president has said, the U.S. is reviewing the way that we gather intelligence to ensure that we properly balance the security concerns of our citizens and allies with the privacy concerns that all people share," Carney said at the White House briefing.

"Both leaders agreed to intensify further the cooperation between our intelligence services, with the goal of protecting the security of both countries and of our partners, as well as protecting the privacy of our citizens," he said.

Obama and Merkel spoke over the phone after the chancellor reportedly received information that U.S. intelligence may have been monitoring her cellphone. Merkel's spokesman said the chancellor made clear in the call that she views such practices, if confirmed, as "completely unacceptable," according to the Associated Press.

Pressed further if it was possible that a broader sweep may have indirectly picked up some of Merkel's communications, Carney reiterated, "We gather foreign intelligence just like agencies - similar agencies of other countries, but we are working to - as the president has said - to review the way that we gather intelligence, to ensure that we properly balance both the security concerns of our citizens and allies with the privacy concerns that everyone shares."