Mexico's former ambassador to the United States said Tuesday that 30 million illegal immigrants currently live in the U.S., far surpassing the official U.S. government estimate of 11 million.

"If you were to deport the 30 million undocumented immigrants in the United States, that's going to cost you about 130 billion dollars," former ambassador Arturo Sarukhan told MSNBC Tuesday during a critique of Republican presidential front-runner Donald Trump's newly released immigration plan, reported Newsmax.

Sarukhan continued to talk as a graphic flashed on the screen saying it would cost $137.5 billion to deport 11 million illegal immigrants.

Towards the end of the interview, Sarukhan mentioned a 2014 Senate proposal regarding immigration and suggested that there were 11.3 million undocumented foreigners in the U.S., a figure he repeated again before the interview ended. He did not address his previous assertion that 30 million illegals are in the U.S.

Like the real U.S. unemployment rate, the actual number of illegal immigrants in the country is somewhat of a mystery, but the federal government estimated in 2012 that the number is close to 11.4 million. Many conservatives and immigration watchdog groups contend that the actual number is closer to 30 million, Breitbart noted.

Back in July, Trump said his sources told him the government number is wrong. "I am now hearing it's 30 million, it could be 34 million, which is a much bigger problem ... I am hearing it from other people, and I have seen it written in various newspapers. The truth is the government has no idea how many illegals are here," he told MSNBC.

A group of former Border Patrol agents penned an open letter in 2013 claiming that the number of illegals in the U.S. is around 18-20 million, and a 2005 Bear Stearns report estimated that the number could be as high as 20 million, reported The Washington Times.

Trump released his immigration reform plan on Sunday, aptly titled, "Immigration Reform That Will Make America Great Again," as HNGN previously reported. The proposal reasserts Trump's call for a wall to be built along the southern border, which he would force Mexico to pay for by increasing fees on border movement between the U.S. and Mexico, according to The New York Times. His plan would also put an end to birthright citizenship, strengthen the "enforcement arm" of the Immigration and Customs Enforcement office, and impound all remittance payments derived from illegal wages.

Sarukhan told MSNBC that Trump's plan would be an "unmitigated disaster."