KABUL, Afghanistan (AP) — The Obama administration on Thursday stepped up efforts to press Afghanistan’s two feuding presidential candidates to end their dispute over June elections, accept the results of an ongoing audit of all ballots and form a national unity government by early September.

On an unannounced visit to Kabul, U.S. Secretary of State John Kerry made personal appeals to both candidates — former Foreign Minister Abdullah Abdullah and former Finance Minister Ashraf Ghani Ahmadzai — to understand the urgency of finding a resolution before the upcoming NATO summit in Wales on September 4, according to officials traveling with Kerry. At that summit, NATO leaders are hoping to make decisions about their nations’ roles in Afghanistan after the end of the year, when most combat troops will be withdrawn.