Obama, Cameron discussed tapping oil reserves
Obama raised the issue during a broad bilateral meeting at the White House, according to a UK official with knowledge of the discussion.
Asked about the talks, a senior Obama administration official said: "No agreement was reached. We will continue to work together to address energy security and oil price issues."
While U.S. officials have said for weeks that they will consider all possible measures - including a release from the U.S. Strategic Petroleum Reserve (SPR) - to prevent prices from derailing a nascent economic recovery, Wednesday's meeting was the clearest indication that diplomatic talks were moving ahead.
Discussions could last as long as several months before any decision is made, one of the sources said.
Obama's approval ratings have come under pressure from rising gasoline prices, which have hit seasonal record highs, and the White House is eager to show exasperated Americans that it is doing all it can to keep fuel costs in check.
Unleashing emergency stockpiles would almost certainly prompt attacks from Republicans, however, who blame Obama's energy policies for high prices at the pump and could paint an SPR release as a gimmick to appease voters during an election year.
Benchmark crude oil prices have rallied 16 percent this year as new European and U.S. sanctions begin to choke off crude exports from Iran, while supplies from other smaller producers including Sudan and Syria have also been cut.
A release of reserves would be the second such intervention in the past year after the world's consumer nations sanctioned their biggest ever release last June in the wake of Libya's civil war.
Prior to that, U.S. officials had spent about six weeks quietly shoring up the support of International Energy Agency (IEA) member nations and key OPEC allies.
While likely to be popular with many Americans, tapping the SPR alone could antagonize allies in Europe, several of whom remain unhappy over last year's action and are unlikely to back another release.
The head of the Paris-based IEA, Maria van der Hoeven, has said in recent weeks she sees no current need for consuming nations to release strategic reserves.
Analysts say that Obama would likely prefer to press forward with the legitimacy of full IEA member support, but realistically may have to settle for the backing of just a handful of other consumer nations.