On the eve of a consequential meeting with President Obama, British Prime Minister David Cameron called the release of the so-called Lockerbie bomber "completely and utterly wrong."

Several senators are pressing the Justice Department to investigate whether BP pressured the British government to release Abdel Baset al-Megrahi to protect its oil interests in Libya.

The British government is denying the charge and, so far, the White House is sounding circumspect.

"We opposed the release of the Lockerbie bomber [and] we made that opinion known," said White House press secretary Robert Gibbs. "We were unaware of any role that [BP] played in delivering an opinion."

As to whether the matter should be investigated, Gibbs said, "in many ways that will be up to the British government to determine."

The ongoing BP oil crisis in the Gulf of Mexico and any role BP played in the Lockerbie case are among the topics the leaders are expected to address Tuesday, along with the pending British pullout of 1,000 troops from Afghanistan.

Obama, whose relationship with previous Prime Minister Gordon Brown was awkward and distant, will be looking to make a closer ally of Cameron. The United States and Britain enjoy what both term a "special relationship," with some times more special than others.

For his part, Cameron hopes to quiet the relentless drumbeat of criticism of BP from Washington, and show constituents that he can manage a relationship with the leader of the free world that improves on former Prime Minister Tony Blair's reputation as America's "poodle."

Ahead of his visit, Cameron expressed concern about how the BP oil spill is hurting the company and pension funds invested in the now-troubled oil giant.

Gibbs described the two leaders as being more in agreement than otherwise, including on BP's future obligations for the oil spill and their shared aversion to the release of the Lockerbie bomber.

Cameron, who become prime minister in May and after al-Megrahi was released, told the BBC he opposed the move. The Libyan served eight years of a life sentence and was greeted as a hero when he returned home.

"I could not have been more clear that I thought the decision to release al-Megrahi was completely and utterly wrong," Cameron said.

At the same time, Cameron's government has resisted reopening the matter. Secretary of State Hillary Clinton has asked Britain and Scotland, which has an independent legal system, to review the facts surrounding the release.

The convicted bomber, said to be suffering from the last stages of prostate cancer and released from Scottish prison on compassionate grounds nearly a year ago, is alive and reportedly living in a seaside villa in Libya.

Al-Megrahi was the only person convicted in the 1988 bombing of a Pan Am flight over Scotland. Of the 270 people killed in the incident, 189 were Americans. The Senate Foreign Relations Committee has announced plans for its own probe into BP's involvement in the matter.