Khan made the remarks while speaking to a group of foreign journalists on Saturday, days after he accused an unnamed "foreign power" - in a clear reference to the United States - of funding a "conspiracy" to topple his democratically-elected government.
"The move to oust me is (a) blatant interference in domestic politics by the United States," Khan said, as he faces a no-confidence vote on Sunday that could mean the end of his premiership.
Also in a televised speech on Thursday, Khan claimed that a foreign country is encouraging a no-confidence vote because of his visit to Russia last month.
He even named the United States as the origin of a "message" that he said proved a foreign country was meddling in Pakistan's affairs.
According to Reuters, citing local media, the message was in a briefing letter from Pakistan's ambassador to Washington recording a senior US official telling him they felt relations would be better if Khan left office.
The White House has denied that the US is seeking to remove Khan from power after he made similar accusations in the past days.
The no-confidence motion against Khan is expected to take place on Sunday.
The opposition needs a simple majority of 50 percent plus one to topple the ruling Pakistan Tehreek-i-Insaf government.
Khan needs 172 votes in the 342-seat house to foil the bid. Some defections in the PTI and cracks in his coalition partners have dented his chances to accumulate the 172 votes, needed to hold on to power.
If Khan loses on Sunday, he would be the first prime minister to be removed through a vote of no confidence.
The cricketer-turned-politician has been accused by the opposition of mishandling the economy and foreign policy since coming to power in 2018.
His embattled government has been banking on the International Monetary Fund (IMF) to release a 6 billion-dollar rescue package, but the move has been obstructed by the US.
Khan has said he will never resign his post.
Meanwhile, Khan has called on his supporters to take to the streets to peacefully protest against what he said was a "conspiracy" hatched outside Pakistan to unseat him.
"I want you all to protest for an independent and free Pakistan," he said during a public question and answer phone-in broadcast by state media on Saturday.
Khan, who had formed a coalition government after winning the election in 2018, has lost the crucial support of the country's powerful military, making way for a strong opposition that wants him to step down.
He has accused the opposition of conspiring with Washington to remove him because he won't take the West's side on global issues against Russia and China.
Khan, who called his opponents “robbers, cowards, deceivers,” said the country's foreign office summoned the acting US charge d'affaires on Friday to lodge a strong protest over Washington’s meddling in the internal affairs of the country.
