U.S. President Barack Obama said he and British Prime Minister David Cameron would discuss their nations' pace of withdrawal from Afghanistan Wednesday.

The two leaders "have a strategy that will allow us to responsibly wind down this war," Obama told reporters before leaving for Dayton, Ohio, Tuesday to watch the Western Kentucky Hilltoppers beat the Mississippi Valley State Delta Devils 59-58 in the NCAA Division I men's college basketball tournament.

"We're steadily transitioning to the Afghans who are moving into the lead, and that's going to allow us to bring our troops home," Obama said.

The long-term war strategy has gained new interest following Sunday's massacre of 16 civilians, including nine children, in Afghanistan's Kandahar Province, allegedly by a U.S. Army sergeant.

Obama and Cameron planned to stay the course on ending their nations' Afghan combat role by mid-to-late 2013, despite obstacles and criticism, and were expected to reach a tentative agreement at the White House Wednesday on the Afghan withdrawal timetable, officials told the British newspaper The Guardian.

The leaders planned to discuss Iran. British Ambassador to the United States Peter Westmacott told reporters Cameron was adding his voice to Obama's in discouraging an Israeli military strike on Iranian nuclear facilities.

Cameron supports Obama's vow that Iran will not be permitted to acquire nuclear weapons, and believes, like Obama, military force must be an option, Westmacott said.

But an Israeli strike could "unleash a whole variety of different consequences" and might backfire by strengthening the Iranian regime and the Iranian people's resolve to acquire nuclear status, he said.

"We are, all of us, concerned about what might flow from a decision to take precipitate military action," he said.

U.S., Israeli and European officials, supported by U.N. weapons inspectors, assert Iran plans to build nuclear weapons. Tehran insists its nuclear program is for peaceful civilian uses only.

Israel has repeatedly said it would not let Iran reach nuclear-weapons capacity and has declared it has an option to launch a military strike against Iran's nuclear facilities as a last resort.

Cameron was expected to press Obama Wednesday for tighter diplomatic and economic sanctions against Iran, a senior British official in London told The New York Times.

"There's a lot more to be done to turn up the pressure, to turn up the dial," the official, whose name was not reported, said.

Obama, Vice President Joe Biden, first lady Michelle Obama and Biden's wife, Jill Biden, were to welcome Cameron and wife Samantha Cameron to the White House at 9 a.m. EST Wednesday.

Obama and the prime minister were to meet privately in the Oval Office at 10 a.m., followed by an expanded meeting with the U.S. and British delegations, including Joe Biden, in the Cabinet Room, which adjoins the Oval Office and overlooks the White House Rose Garden, the White House said Tuesday night.

The leaders were to hold a joint news conference in the Rose Garden at 12:05 p.m.

At 7 p.m. the president and first lady were to welcome David and Samantha Cameron back to the White House at the columned North Portico, followed at 7:30 p.m. by an official photo taken at the ceremonial Grand Staircase, connecting the executive mansion's State Floor and second floor, and then a State Dinner and reception on the South Lawn starting at 8:30 p.m., the White House said.

White House spokesman Jay Carney said the special attention Cameron, leader of Britain's Conservative Party, was receiving reflected "the kind of relationship that we have with the United Kingdom, and that previous presidents have had with previous prime ministers."

He said Obama received "remarkable hospitality" when he visited England last year. Carney said Britain was "a key ally across the globe."

Comparing Britain with China, Carney said Britain invests "140 times the amount of China in the United States.

"I don't think most people know that," he said.