The newly-appointed ambassador to the United States, Aizaz Chaudhry, on Thursday said that the Taliban had entered Pakistan as migrants, who had been told to steer clear of militant activities if they wanted to stay in the country.

Chaudhry, whose career as a foreign service officer spans over 36 years of multilateral and bilateral experience, was speaking at a seminar at the Air University Islamabad on matters of national security.

"We will not tolerate that the Taliban operate from here to carry out terror attacks across the border. The unrest in Afghanistan will not be allowed to infiltrate into Pakistan," Chaudhry said, when asked for a comment on the supposed distinction between "the good and the bad" Taliban.

The newly-appointed ambassador to the US said that the state wants Afghanistan and Taliban to enter dialogue.

"Billions of dollars have been spent on establishing peace in Afghanistan, but to no avail," Chaudhry added, saying that terrorism from Afghanistan is now spreading into Pakistan where elements are trying to destabilise the country and sabotage major events like the Pakistan Super League.

"We will not be pressurised by this so-called 'Do more' ideology being pushed on us. We're working on full capacity to counter terrorism and we will continue with our efforts in full force," he added.

Chaudhry also said that Pakistan is under threat from the militant Islamic State (IS) group, which may head to the country as the Syrian conflict nears an end.

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"It has been established that IS is operating in Afghanistan, and as a neighbouring country, Pakistan has severe reservations regarding the situation," he added.

He noted that the IS had posted pamphlets all over Peshawar, but the masses rejected them, adding that the much-feared militant group cannot establish a base in Pakistan as the nation is united when it comes to opposing terrorism.

"Action has already been initiated against terror outfits involved in sectarian violence in the country," Chaudhry said when he was asked about government's efforts to curb sectarian bloodshed.

"Nobody can isolate Pakistan," he maintained.