Israeli Prime Minister Benjamin Netanyahu called U.S. wiretapping of his predecessor, Ehud Olmert, "unacceptable", Agence France-Presse reported. 

"Given the close relations between the United States and Israel, there are things we cannot do, and that is unacceptable for us," Netanyahu said at a meeting of his Likud party on Monday.

According to a New York Times report last week, U.S. and British intelligence agencies monitored more than 1,000 targets in upwards of 60 countries between 2008 to 2011 and tapped the communications of then premier Olmert, among other foreign leaders, according to secret documents revealed by intelligence contractor Edward Snowden.

Netanyahu said he had asked for the reports to be verified, AFP reported.

"We do not spy on the president of the United States or the White House. The rules have been made clear," said Israeli Intelligence Minister Yuval Steinitz on Sunday. "We have made certain commitments on the matter and we honor them." 

Following the 1985 arrest in Washington of former U.S. Navy analyst Jonathan Pollard, Israel and its close strategic ally had agreed not to spy on each other. Pollard was accused of giving Israel thousands of secret documents about U.S. espionage in the Arab world, AFP reported. After Pollard was sentenced to life imprisonment by a U.S. court, fresh calls for his release were made with reports of Americans spying on their friends.

According to AFP, Netanyahu met Pollard's wife on Monday and told her of his government's efforts to secure the release of her husband, who obtained Israeli citizenship in 1995.

The Israeli leader told his cabinet on Tuesday that the efforts to obtain Pollard's release were "neither conditional on, nor related to, the latest events, even though we have given our opinion on these developments," without elaborating.