(CNN) -- Israel reacted angrily Sunday to recent reports that British and U.S. intelligence officials spied on top Israeli officials' e-mails.
"The tracking after prime ministers and defense ministers is not legitimate and not acceptable to us," the spokesman of Intelligence Minister Yuval Steinitz said, according to a CNN translation. "There is an intelligence alliance between (the United States and Israel) at an unprecedented level, and we are sharing the most sensitive (intelligence) material."
On Friday, The Guardian, The New York Times and Der Spiegel newspapers reported that the communications of more than 1,000 organizations and individuals were monitored from a facility in southwest England.
Der Spiegel, a German publication, wrote: "At least four Israeli targets are named in the lists, including an email address named as the 'Israeli prime minister.' "
The document, among those provided by former National Security Agency contractor Edward Snowden, is from early 2009.
A spokeswoman for the NSA said Friday the United States collects foreign intelligence just as many other nations do.
"The intelligence community's efforts to understand economic systems and policies, and monitor anomalous economic activities, are critical to providing policymakers with the information they need to make informed decisions that are in the best interest of our national security," Vanee Vines said.
None of the newspapers published any of the documents they were shown, and the volume of information collected on any particular individual or organization is unclear.
On Friday afternoon, the U.S. State Department's spokeswoman said Secretary of State John Kerry has been communicating with U.S. allies.
"The secretary has been a part of engaging on this process, whether it's discussing with foreign countries their concerns, attempting -- working to alleviate those," spokeswoman Jen Psaki said. "Our goal remains to continue to strengthen our intel gathering processes and relationships. But I'm not going to speak to different reports or allegations."
President Barack Obama vowed this month to find ways of reforming the NSA, though he also defended the agency's work.
Obama is going through 40 recommendations made last week by the independent presidential Review Group on Intelligence. He will make a "definitive statement" on surveillance programs in January after he returns from a Hawaiian vacation.
Israel has said it would never spy on the U.S. in the wake of the conviction of a former U.S. Navy intelligence analyst who was caught spying for Israel in 1985.
Jonathan Pollard was sentenced to life in 1987 after he was convicted of one count of espionage, and since then many Israeli leaders have appealed to U.S. presidents for his release.
Israeli Prime Minister Benjamin Netanyahu said the newest revelations have no bearing on the case.
"We do not need any special event in order to discuss the release of Jonathan Pollard. We are dealing with it. I am dealing with it, with all U.S. presidents, including President Obama, all the time, including now," he said Sunday at the weekly Cabinet meeting. "We hope that the conditions will be created that will enable us to bring Jonathan home. This is neither conditional on, nor related to, recent events, even though we have given our opinion on these developments."
Pollard has dual citizenship.
CNN's Tim Lister and Michael Schwartz contributed to this report.