Obama, in his conversation with Afghan President Hamid Karzai, also discussed the Afghanistan-Pakistan-Iran trilateral meetings held last week in Islamabad.

"They agreed to speak again soon to remain closely aligned as both countries continue our efforts to achieve common goals, and work to forge a long-term partnership," the White House said in a statement.

The Wall Street Journal reported on Wednesday that the U.S. and Afghan governments had begun secret three-way talks with the Taliban, based on an interview it conducted with Karzai.

Afghanistan's ambassador to Pakistan, Umar Daudzai, told Reuters on Thursday that contacts with the Taliban were at the "exploratory" stage.

The Afghan Taliban announced last month it would open a political office in Qatar, suggesting the group may be willing to engage in negotiations.

(Reporting By Alister Bull; Editing by Peter Cooney)