Ghani, who is also a presidential candidate, while addressing supporters at a gathering in Kabul on Sunday said that only the Afghan government has the authority to negotiate with the Taliban and reach an agreement with the group.
His comments came as State Minister for Peace Abdul Salam Rahimi said that direct talks between the Afghan government and Taliban will start within the next two weeks and it will be held in a European country.
However, US Special Envoy Zalmay Khalilzad said the talks will happen after the US "concludes its own agreement" with the Taliban and that the negotiations "will take place between the Taliban and an inclusive and effective national negotiating team consisting of senior government officials, key political party representatives, civil society and women", reported Tolo News.
Ghani addressing the campaign, said: "It should be clear to all that only an elected government can bring peace to this country."
He said Taliban will "regret" if they failed to use the current opportunity for peace in the country.
"We have made big steps for peace. We established the National Unity Government to prove to the people that we are not following power. We are trying to serve the people," he said.
Meanwhile, the Taliban on Sunday said they will not hold direct talks with Afghan government and rejected a statement from the State Minister for Peace about plans to hold such a meeting within the next two weeks.
A spokesman for the Taliban, Zabihullah Mujahid, said in a tweet on Sunday that the talks will be held among all parties and that the Afghan government will attend as a participant, not as the other side of the talks.
Mujahid said the intra-Afghan negotiations will happen after the announcement of a timetable for the withdrawal of US forces from Afghanistan.
Rahimi said on Saturday that they have started consultations with different stakeholders on forming a 15-member negotiating team who will lead the peace talks with the Taliban.
Rahimi called on the warring sides to reduce the level of violence ahead of the direct talks.
The Taliban statement came as Vice Presidential candidate Amarullah Saleh escaped a deadly suicide bombing and gun attack on his office on Sunday evening.
( With inputs from IANS )