Afghan President Ashraf Ghani lashed out at Pakistan at the Kabul Process on Tuesday, alleging that it is waging an "undeclared war of aggression" against Afghanistan.

Issuing a stinging rebuke aimed towards Pakistan before a gathering of 23 nations, the European Union, the United Nations and Nato, Ghani asked: "What will it take to convince Pakistan that a stable Afghanistan helps them and helps our region?"

Ghani's fresh criticism comes as the Kabul Process, a forum for the discussing security and political issues in the country, is underway.

Pakistan and Afghanistan have long accused each other of turning a blind eye to militants operating along their porous border, and both forces exchanged fire over a border dispute last month.

Despite strained bilateral relations, Pakistan is participating in the multinational conference, having sent a two-member Pakistani delegation headed by Additional Secretary UN and Economic Cooperation Tasneem Aslam.

Ghani also issued an ultimatum to the Taliban, calling on the militants to embrace peace or “face consequences”.

“We are offering a chance for peace but this is not an open-ended offer. Time is running out... this is the last chance, take it or face consequences,” Ghani said at the international peace conference in Kabul.

“If Taliban wants to join peace talks, the Afghan government will allow them to open an office, but this is their last chance,” Ghani said.

Talking about the current situation of unrest in the country, the Afghan president said that last week's Kabul truck bombing killed over 150 people, making it deadliest attack since 2001.

Past attempts at peace talks have failed. The Taliban have refused to negotiate with the government until all foreign forces leave, and still refer to themselves as a government in exile, angering authorities in Kabul.

With additional reporting by Sammer Abbas.