U.S. Democratic presidential candidate Barack Obama had breakfast with U.S. troops in the Afghan capital on Sunday and talked about their experiences in the country that has seen a sharp rise in violence this year.

Obama, part of a congressional delegation, was also due to meet Afghan President Hamid Karzai later in the day, the Afghan Foreign Ministry said.

Obama's trip, which will also take him to Iraq, Jordan, Israel, Germany, France and Britain, is aimed at bolstering his foreign policy credentials and answering critics who say he does not have the experience to be armed forces' commander-in-chief.

"They had breakfast at Camp Eggers with the soldiers," said U.S. Lieutenant Colonel Dave Johnson. "They sat with the soldiers, shared stories with the soldiers about what is going on in Afghanistan ... shared experiences."

Obama arrived in Afghanistan on Saturday and was briefed by the commander of NATO-led forces in the east of the country, where mostly U.S. troops have seen a 40 percent rise in Taliban attacks this year. Together with fellow senators Jack Reed and Chuck Hagel, Obama then travelled to the eastern city of Jalalabad where he met the provincial governor, Gul Agha Shirzai, a former anti-Taliban warlord who has claimed some success in bringing relative order to the frontier province.

It is more than six years since U.S.-led and Afghan forces toppled the Taliban for sheltering al Qaeda leaders behind the Sept. 11 attacks, but violence has risen sharply in recent months and there are few signs the insurgency is weakening.

NATO says part of the reason for the rise in violence is de facto ceasefires between militants and the military in Pakistan's lawless tribal belt, which provides the Taliban with sanctuaries from which to launch attacks into Afghanistan.

Obama wants to send two more brigades, or some 7,000 U.S. troops, to Afghanistan and shift the emphasis from what he calls the Bush administration's "single-minded" focus on Iraq. He has called for a withdrawal of U.S. troops from Iraq in 16 months.

The United States has about four times more troops in Iraq than the 36,000 it has in Afghanistan. But more of its soldiers were killed in Afghanistan in both May and June than in Iraq.