New Delhi, April 1 : US Assistant Secretary of State for South and Central Asian Affairs Donald Lu had reportedly in a meeting with Pakistan Ambassador Asad Majeed warned that there could be implications if Pak Prime Minister Khan survived the opposition's no-confidence motion in the National Assembly, Dawn reported. The Natio­nal Security Committee (NSC) on Thursday expre­ssed "grave concern" over the US meddling in Pakistan's internal affairs and decided to lodge a strong protest. The meeting was conve­ned to discuss Prime Mini­ster Imran Khan's claim that a foreign country, which he later identified as the US, had sent a threatening message through Pakistan's envoy. Meanwhile, the Foreign Office spokesman in a brief statement issued, said that as per the NSC decision, the "demarches have been made through diplomatic channels". The NSC, which is the top civil-military forum, after deliberating on the contents of the US message conveyed by Pakistan's ambassador through a cable on March 7, expressed "grave concern" over it. The statement by the Prime Minister Office on the meeting did not name any country, but after Imran Khan's gaffe it became obvious that the unnamed state was none other than US. The NSC members described the language used by the "foreign official" as "undiplomatic". /IANS