London, Sep. 11 : US President Barack Obama reportedly blasted British Prime Minister Gordon Brown on the phone for his decision to set the Lockerbie bomber free, indicating that the US-Britain relations have hit a new low.

During his 40-minute telephone call, Obama made it clear that he was "disappointed" that cancer-stricken Abdelbaset Ali al-Megrahi was freed, The Sun reports.

White House press secretary Robert Gibbs said in a statement: "The United States has expressed regret at the Scottish decision to turn over to Libya the Lockerbie prisoner, but Obama had not done so personally to Brown.

The White House rarely releases details of phone conversation with British PM.

Downing Street tried to play down the call. It said the leaders' conversation was "warm and substantive", adding: "The leaders concluded the special relationship was as strong as ever."

However, the optimism of the ruling party was not shared by the Tories, who claimed that the decision had caused irreparable damage to relations between the two closest allies.

Shadow foreign secretary William Hague said last night: "The decision to release Mr al-Megrahi has damaged our relationship with our closest ally." (ANI)