Germany's leading medical association, along with pharmaceutical manufacturers in the country, pledged Monday that they would not sell a drug necessary for lethal injections to the US.

In a letter to the companies, German Health Minister Philipp Roesler had asked that wholesalers not supply the US sodium thiopental or any other drug that could be used for executions.

Sodium thiopental is one of three drugs used in the lethal injection process. It renders prisoners unconscious before two other "killer drugs" are administered.

The German Medical Association told The Associated Press that the nation's doctors were standing behind Roesler's request.

"We are calling on the German pharmaceutical industry to send a clear signal that it recognizes its ethical responsibility and refrain from selling any drugs to the United States that could be used in carrying out the death penalty," the German Medical Association's Frank Ulrich Montgomery said.

"This is not about money, but ethical principles," he added.

Three German makers of sodium thiopental -- Nycomed GmbH, Inresa GmbH and Rotexmedica GmbH -- also told the AP that they would not export the drug to the US. The three companies said they currently had no agreements to do so.

"Thiopental is not the problem," Inresa managing director Bruno Wassmer explained. "The problem lies somewhere else: The death penalty must be abolished."

Hospira Inc., of Lake Forest, Illinois, announced Friday that it would no longer manufacture sodium thiopental at its plant in Italy. Hopsira was the last US-owned manufacturer of the drug.

The company said that it never agreed with the use of the drug for capital punishment, and it "exited the market" because of fears that it could be held liable by Italian authorities.

The news agency also noted that executions planned for Arizona, California, Kentucky, Ohio and Oklahoma faced delays due to the drug's shortage.

The US Food and Drug Administration (FDA) helped Arizona and California obtain a limited supply of the drug from England last fall.

The Nebraska Department of Corrections obtained 500 grams of sodium thiopental from an unnamed Indian company earlier this month.

The death penalty was still law in 35 states, according to the Death Penalty Information Center. The practice declared illegal by just 15 states.

Illinois was seen as likely to become the next state to abolish capital punishment. Lawmakers passed a bill last week that would end the death penalty in the state, but Governor Pat Quinn (D) had delayed signing it into law.

The State of Texas was by far the biggest supporter of the death penalty, with 17 executions in 2010. Ohio had eight executions, and Alabama had five.

Over 1,200 people have been put to death since 1976, when the Supreme Court ended its nationwide ban. There were over 3,200 inmates were death row at the time of this story's publication.