since Obama won a second term, Cameron will receive a detailed briefing from the FBI on the Boston bombings to see if Britain can learn lessons from how the United States responded. He is also expected to express his condolences to the victims of the attack.
Global diplomacy will feature prominently during his trip and the British leader is hoping the US president will help him prepare the ground for next month's G8 summit in Northern Ireland and that the two - along with Russia - can help find a political settlement for Syria.
Cameron's three day visit will begin at the White House in Washington and finish in New York where he is expected to take part in UN talks on agreeing new global development goals.
His visit underlines the continued importance of the "special relationship" between Britain and the United States, even as cuts to Britain's defence budget and talk of Britain leaving the European Union are causing anxiety among senior US policymakers who fear their close ally is growing weaker.
Cameron phoned Secretary of State John Kerry to discuss Syria before the trip. A spokesman from Cameron's office said he had talked about "how the UK, Russia and America could work together to successfully achieve the plan of a peace conference by the end of the month".
Cameron was also keen to discuss with Obama how Britain and America could work together to establish a stronger and more credible opposition inside Syria, the spokesman added.
EU-US trade deal
But it is the prospect of an EU-US trade deal and the lucrative dividends that such an agreement could bring both countries that Cameron was keen to stress before the trip even as one of his own government ministers said he thought Britain should leave the EU.
In particular, he is hoping Obama will help him clinch an agreement to start talks on such a trade deal in the margins of the G8 summit, an achievement he believes would give the global economy a shot in the arm at a time when his own country and many others are seeing only a fragile economic recovery.
"Britain and America can once again lead the way in meeting the greatest challenge of our time: securing the growth and stability on which the prosperity of the whole world depends," Cameron wrote in an article for the Wall Street Journal.
He said an EU-US trade deal would boost the British economy by 10 billion pounds a year and the US economy by 63 billion pounds annually.
"When times are tough, some want to put the barriers up, to look inwards, and to protect themselves from the world. But Britain and America stand for a better way," he wrote in the same article.
Cameron is hoping Obama will also help him turn high-flown rhetoric on cracking down on global tax evasion into a meaningful international agreement at the G8 summit.
"We must fight the scourge of tax evasion by promoting a new global standard for automatic information exchange between tax authorities," Cameron said.
Using some of his strongest language on the subject yet, he added: "We must lift the veil of secrecy that too often lets corrupt corporations and officials in some countries run rings around the law."
A global standard for resource-extracting companies that obliged them to report all payments to governments across the world would be also be an important step forward, he said.