KABUL—Afghan President Ashraf Ghani on Saturday said he began consultations on how to unite the country and prevent additional bloodshed, as the Taliban tightened their grip, seizing further provincial capitals.

Mr. Ghani—in his first public remarks considering that the Taliban swept as a result of southern and western Afghanistan, capturing the major cities of Kandahar and Herat—said his precedence is to remobilize the Afghan security forces that surrendered en masse.

“As a historic obligation, I am seeking to not permit the war that has been imposed on the Afghan people today bring about the additional killing of innocents, the loss of 20 a long time of achievement, the destruction of public establishments and longstanding instability,” Mr. Ghani said in a video concept posted on social media, the country’s flag unfurled powering him.

Mr. Ghani has come less than rising pressure from Afghan politicians to resign so that a transitional governing administration headed by an individual else could negotiate a stop-fire with the Taliban and prevent the storming of Kabul, the country’s funds. He gave no indication he intends to do so, at least not immediately.

Afghan negotiators, the Taliban, the U.S. and other nations are engaged in discussions in Doha, Qatar, on how to locate a political settlement to the war, with the elimination of Mr. Ghani becoming a vital Taliban demand.