The development comes after the National Security Committee decided that Pakistan would issue a “strong demarche” to the country in question both in Islamabad and in the country’s capital through proper channels in keeping with diplomatic norms.

Prime Minister Imran Khan had presided over the meeting in Islamabad. Federal ministers of defence, energy, information & broadcasting, interior, finance, human rights, planning, development & special initiatives, the chairman of the Joint Chiefs of Staff Committee, services chiefs, national security adviser and senior officers attended the meeting.

NSC briefing: Pakistan to lodge formal protest over 'threatening letter'

On Thursday, NSA Moeed Yusuf had briefed the committee on the formal communication of a senior official of a foreign country to Pakistan’s ambassador in the said country in a formal meeting, which was duly conveyed by the ambassador to the Ministry of Foreign Affairs.

The committee expressed “grave concerns” at the communication, terming the language used by the foreign official as “undiplomatic.” It concluded that the communication amounted to “blatant interference in the internal affairs of Pakistan by the country in question,” which was unacceptable under any circumstances.

Participants of the meeting also endorsed the cabinet’s decision in the special cabinet meeting held on Wednesday to take the parliament into confidence through an in-camera briefing to the National Security Committee of parliament.