Senior US diplomats had multiple conversations, including at least two private face-to-face meetings, with top members of Bhutto's Pakistan People's Party to discuss threats on the Pakistani opposition leader's life and review her security arrangements after a suicide bombing marred her initial return to Pakistan from exile in October, the officials said on Monday.

The intelligence was also shared with the Pakistani government, the officials said.

Much of what was passed on dealt with general threats from Taliban extremists and Al-Qaida sympathisers and "was not actionable information."

The officials said Bhutto and her aides were concerned, particularly after the October attack, but were adamant that in the absence of a specific and credible threat there would be few, if any, changes to her campaign schedule ahead of parliamentary elections.

"She knew people were trying to assassinate her," said an intelligence official. "We don't hold information back on possible attacks on foreign leaders and foreign countries."

The official added, however, that while the US could share the information, "it's up to (the recipient) how they want to take action."