The militant offensive began simultaneously in northern and southern regions, while the Taliban and government delegations were preparing for the next round of peace talks in Doha.
Fierce battles were fought on Thursday night for control of Kandahar and Herat - the two largest cities after Kabul - in the south of the country.
In the north, the Taliban captured Pol-e-Khomri, which is located near the strategic Kotal-e Salang Pass linking the northern part of Afghanistan with Kabul. Early this week, the militants captured the city of Kunduz, the so-called gateway to Central Asia. Fighting continues in the north for Mazar-i-Sharif, the fourth-largest city in Afghanistan and the provincial capital of Balkh. In the event of its fall, the government seated in Kabul will be cut off from neighbouring Uzbekistan.
As of Friday, Taliban militants have occupied most of the key provinces and largely control the territories bordering neighbouring states.
Thousands of people are fleeing to Kabul from northern provinces, while the United States, the United Kingdom and Canada have decided to evacuate their citizens and diplomatic personnel from the Afghan capital.
*The Taliban is a terrorist organisation, banned in Russia and many other countries.