Pakistani premier's security beefed up after assassination threat: Minister

The statement by Fawad Chaudhry came a day after Faisal Vawda, a former minister, made similar claims and said Khan's life was in danger, Anadolu Agency reported.

The remarks come in the backdrop of a no-confidence vote against the premier this weekend, and claims by Khan that the US, Pakistan's longtime ally, has hatched a conspiracy to oust him for his "independent foreign policy."

He has blamed opposition parties for being "stooges of the foreign power", it reported.

In an address to the nation on Thursday, the prime minister reiterated that he would not step down, but rather contest the no-confidence vote.

He said: "On March 7, we received a letter from America. Okay, let's not name any country. We received a letter from a foreign country.

"It was an official document based on notes our ambassador took during a meeting with officials of that country, which says we will spare Pakistan if Imran Khan goes as result of the no-trust motion, otherwise it (Pakistan) will have to face the consequences."

White House spokeswoman Kate Bedingfield rejected the claims in a press briefing, saying: "There is absolutely no truth to that allegation."

Earlier, Anadolu Agency also reported that Pakistan's National Security Committee condemned the purported communique, saying the language used was "unacceptable" and "undiplomatic."

The top civil-military body said the communication "amounted to blatant interference in the internal affairs of Pakistan by the country in question, which was unacceptable under any circumstances."

Late Thursday, the Foreign Ministry also lodged a formal protest with the US over the "threatening" letter.

The combined opposition, led by the Pakistan Peoples Party and Pakistan Muslim League-Nawaz, submitted the no-confidence motion against Khan on March 8, and voting is expected to be held on April 3.

The ruling Pakistan Tehreek-e-Insaf has 155 members in the 342-member National Assembly and needs at least 172 lawmakers to remain in power.

Besides losing support of some allies, about two dozen of Khan's own lawmakers have also announced support for the opposition, which now claims to have a majority in the lower house of parliament and has called on the premier to step down.