Afghanistan's president, Ashraf Ghani, has slammed the Taliban for pushing ahead with its so-called annual spring offensive, despite his "most generous" offer of peace talks.
The Taliban on Wednesday unleashed its new military campaign, code named "Al Khandaq" or the Trench.
The action has since led to scores of coordinated guerrilla-style raids and bombings against Afghan security forces.
On Saturday, the Taliban overran a district center in the troubled northern province of Kunduz, where a major insurgent attack two days ago killed 14 Afghan soldiers.
Separately, a Taliban suicide bomber detonated his explosives-laden vehicle in the early morning Saturday near an Afghan army base in southern Helmand province, killing at least six people and wounding many more.
Speaking in Kabul just hours after the latest insurgent activities, Ghani denounced the Taliban for inflicting violence on their own Muslim nation in the name of a centuries-sacred Islamic battle. He was referring to the title insurgents have chosen for their current spring offensive.
Ghani announced his unconditional offer for peace talks two months ago in a bid to deter the Taliban from intensifying hostilities this year. His initiative included incentives such as allowing the Taliban to open an office in Kabul and to issue travel documents to insurgent negotiators. The offer received support from domestic and international stakeholders.
The Taliban justified launching its new military campaign, saying U.S.-led foreign "occupation" forces were still in control of Afghanistan's "land and air space" and until their withdrawal from the country, no peace talks would be possible with the government.
The Afghan president defended the presence of foreign forces, citing the new insurgent offensive and the Taliban's alleged links with international terrorists.
Ghani, in his address toa gathering of officials, politicians and religious leaders at the presidential palace, said his security forces are resolved to defend the country against the Taliban onslaught.
"If you [Taliban] want war, then we will respond with more power. You must know that our nation stands in front of you," Ghani said to the Taliban.
He went on to urge Afghans to join him in denouncing the insurgents for hurting innocent civilians in the name of religion.
"I call on the entire [Afghan] nation, especially our respectable jihadi personalities, religious scholars and national leaders, to declare through a fatwa [edict] that this [Taliban] war is against Islamic Sharia," Ghani said.
President Ghani said his government is not giving up on efforts to peacefully resolve the Afghan conflict. He reiterated his determinationto undertake political reforms to ensure this year'sparliamentary and district council elections, as well as next year's presidential polls, are held in a fair and transparent manner.
The spike in Taliban attacks is being seen as a major security challenge for the upcoming elections in Afghanistan.
Meanwhile, aTaliban rocket attack in eastern Nangarhar province on Saturdaykilled five civilians and wounded three others.
A provincial government spokesman, Attaullah Khogyani, said three women were among those killed.