David Cameron is due to meet American business leaders to launch a major trade offensive as he bids to shift focus away from the controversies over BP which have so far dominated his first US visit as Prime Minister.
Mr Cameron defended the beleaguered oil giant on Tuesday night as he was repeatedly questioned about its activities at a White House press conference following lengthy talks with President Barack Obama.
The premier insisted he had seen no evidence that BP had "swayed" the decision to free Lockerbie bomber Abdelbaset al-Megrahi and resisted renewed demands from some American politicians for an inquiry.
And he also warned against excessive punishment of BP over the Gulf of Mexico oil spill - insisting it was in neither country's interests to destroy the firm's future and urging critics not to "confuse" the two issues.
The two leaders united in condemnation of the Scottish Executive's decision to release the terminally-ill bomber and Mr Obama welcomed the PM's commitment to publish any relevant UK government documents.
But a group of senators representing victims' families urged him in a meeting last night to reverse his opposition to opening a fresh investigation into the circumstances.
Mr Cameron will begin a busy second day in the US by visiting the Arlington National Cemetery, where he will lay a wreath at the tomb of the unknown soldier and meet British veterans of the Afghanistan conflict.
His visit will be followed by a detailed briefing at the Pentagon about the ongoing military action before he heads to New York to meet senior business figures and to hold talks with United Nations secretary general Ban ki Moon.
"Releasing the Lockerbie bomber, a mass murderer, was completely wrong," Mr Cameron said afterwards, but insisted it was a decision taken by the Scottish Executive and not BP.
Mr Obama said the US had been "surprised, disappointed and angry" by the release but said he would "welcome any additional information that will give us insight into how the decision was made".