In a rare leak that could prove embarrassing to the U.S. government, a British newspaper has printed a seemingly authentic National Security Agency memo ordering stepped-up eavesdropping against countries on the U.N. Security Council whose votes are crucial in the U.S. effort to build support for war against Iraq.

Intelligence experts say the memo, dated Jan. 31, marked "Top Secret" and printed Sunday in The Observer, appears genuine. While no surprise to those familiar with the global eavesdropping the NSA conducts from Fort Meade, the memo may complicate U.S. diplomacy by underscoring that the intelligence agency routinely monitors phone calls, faxes and e-mail not only of hostile countries but of allies and neutral nations.

"As you've likely heard by now, the Agency is mounting a surge particularly directed at the UN Security Council members (minus US and GBR [Great Britain] of course) for insights as to [how] membership is reacting to the on-going debate RE:Iraq," says the memo, from Frank Koza, described as NSA's chief of staff for "Regional Targets."

It asks the unnamed eavesdroppers who got the memo - apparently NSA staff members or their British counterparts at Government Communications Headquarters - to report "the whole gamut of information that could give US policymakers an edge in obtaining results favorable to US goals or to head off surprises."

Specifically, it asks the recipients to target Angola, Cameroon, Chile, Bulgaria and Guinea, while putting "extra focus" on Pakistan.

All the named countries except Bulgaria are among the so-called "middle six" on the United Nations Security Council whose votes are being sought by pro- and anti-war factions, though Pakistan has indicated that it is likely to back the United States. Bulgaria has been a strong supporter of the U.S. and British position that war may be required to disarm Saddam Hussein's regime.

Nine votes are needed in the 15-member Security Council to approve any resolution.

The leaked memo was dated five days before Secretary of State Colin L. Powell's dramatic presentation to the U.N. General Assembly at which he played NSA intercepts of Iraqi officers and showed satellite photos of efforts to hide banned weapons. The memo says the eavesdropping push "will probably peak" after Powell's speech.

A critical speech by the chief U.N. weapons inspector, Hans Blix, is expected Friday, with a Security Council vote possible next week.

Intelligence historians say U.S. eavesdropping at the United Nations is routine. The NSA's predecessors listened in on foreign delegations to the United Nations' founding conference in San Francisco in 1945 and pushed for its permanent location in New York to make listening in more convenient, historians say.

"One would have to have the innocence of an unborn child to believe that espionage doesn't go on every day at the United Nations," said Loch K. Johnson, an authority on intelligence at the University of Georgia. "From a purist point of view, it's unfortunate in a way, because after all, we're the host nation for the United Nations. But the reality is, Europeans and everyone else engages in espionage in New York City, much of it focused on the United Nations."

What is a surprise, experts say, is the apparent leak, which political analysts speculated may have come from someone at the British eavesdropping agency who opposes the push for war. A Senate intelligence committee staff member said the panel would investigate the leak, which would violate federal law designed to protect sensitive intelligence methods.

A former U.S. ambassador with experience in U.N. affairs called the memo's disclosure "shocking."

In a climate of international opposition and skepticism to the war, he said, the perception that the United States is subverting U.N. deliberations through espionage could hurt already shaky public opinion abroad.

"Diplomatically, it may stiffen opposition to the United States," he said. "It's not a helpful development."

A Pakistani official said yesterday that the revelation of the NSA's targeting of his country is disappointing, especially after the close Pakistani-U.S. cooperation in the capture Saturday of a key al-Qaida leader, Khalid Shaikh Mohammed.

"One realizes that high politics is something that Girl Scouts and Boy Scouts don't engage in," the official said. "But for Pakistan, given the level of intelligence sharing with the United States that's going on right now, it means they don't trust what we say behind closed doors. ... It is overkill. It won't be appreciated."

The targeted U.N. delegations had little to say yesterday about the memo. Maria Aliaga, the spokeswoman for Chile's delegation, said her country asked the British foreign minister to investigate the memo's authenticity. How Chile will react "depends on the answer," she said.

The Observer's headline called the NSA eavesdropping "U.S. dirty tricks to win vote on Iraq war," and initial reports from France to Australia picked up similar accusatory language.