A federal judge on Wednesday sentenced a former translator for the U.S. Army in Iraq to 25 years in prison for attempting to sell anti-aircraft missiles and other weapons to the Taliban in Afghanistan.

Alwar Pouryan, a U.S. citizen of Iranian Kurdish descent, was one of seven men indicted in 2011 following an undercover investigation by the U.S. Drug Enforcement Administration into drug trafficking in West Africa.

In meetings in Africa, Ukraine and Romania starting in late 2010, Pouryan and a co-defendant arranged to provide $25 million worth of weapons, ammunition and training to confidential DEA sources posing as Taliban representatives. The DEA sources said they would pay for the weapons with heroin proceeds, according to prosecutors.

The Taliban has long channeled proceeds from Afghanistan’s vast opium harvest -- which has surged in recent years -- toward arming its operations. The North Atlantic Treaty Organization has said that about 50 percent of the Taliban’s funding comes from the drug trade.

In April, U.S. District Judge Naomi Reice Buchwald ruled without a jury that Pouryan, 39, was guilty of one count of conspiracy to provide material support to terrorists and one count of conspiracy to acquire and transfer anti-aircraft missiles.

To endanger "citizens of the country that gave him refuge is heinous," Buchwald said in a Manhattan courtroom before sentencing Pouryan on Wednesday.

Born in a war-torn Kurdish area of Iran, Pouryan came to the United States as a refugee in 1997. He later served as a translator in Iraq for U.S. forces, before entering a murky underground of international arms trading.

During his trial, his lawyer argued that Pouryan had in fact tried to warn U.S. officials about the Taliban arms deal.

Col. Erik Gunhus, the former public affairs officer for Gen. David Petraeus, testified at Pouryan's trial that he received a tip from Pouryan shortly after Pouryan met with the DEA sources. He said he did not act on it because it "wasn't something that I needed to act on or pass forward."

In a long, unscripted statement Wednesday, Pouryan said he was wrongly convicted and challenged Buchwald to say "which part of my story was not true." He also suggested there was more evidence that could prove his innocence.

"I give my life for this country, I serve this country," said Pouryan, who limped into the courtroom with a cane. "I was begging everybody to help me save American lives."

Buchwald told Pouryan his testimony at trial was "not credible."

Pouryan's co-defendant, Oded Orbach, is scheduled to be sentenced on Nov. 1.

"Alwar Pouryan was an American who was all too willing to do business with the Taliban -- agreeing to provide that narco-terrorist organization with lethal, military-grade weapons that would have put countless innocent lives at risk," U.S. Attorney Preet Bharara said in a statement.

Reuters