KABUL, Afghanistan (AP) — A former national security adviser has registered as a candidate for president of Afghanistan and called on the Taliban to engage in peace negotiations to end the country's 17-year war.

Mohammad Hanif Atmar, of the Peace and Moderation party, announced his candidacy Friday in an address to hundreds of supporters at a hotel in Kabul. Afghans go to the polls to elect a new president on July 20.

Current Afghan president Mohammad Ashraf Ghani says he will register to run for re-election in the coming two days .

The Taliban have been steadfast in their refusal to enter peace talks with the Afghan government and have also threatened to halt talks with the United States.