NATO is not happy with Azerbaijan's president for pardoning, promoting and financially rewarding Ramil Safarov, who was serving a life sentence in Hungary for hacking a fellow NATO solider, who was Armenian, to death with an axe eight years ago during a language-training program.

Budapest authorized Safarov's extradition to his homeland, where last week he was given a hero's homecoming. Armenia severed diplomatic ties with Hungary over its decision to release Safarov for the killing of 26-year-old Gurgen Markarian.

"I am deeply concerned by the Azerbaijani decision to pardon Ramil Safarov. The act he committed in 2004 was a crime which should not be glorified, as this damages trust and does not contribute to the peace process," NATO Secretary General Anders Fogh Rasmussen said in a speech Friday at the Azerbaijan Diplomatic Academy, in Baku, Azerbaijan. "There must be no return to conflict between Armenia and Azerbaijan."

The killing, extradition and pardon have deep political undertones. In 1994, a ceasefire was declared between Azerbaijan and its ethnic Armenian popution, parts of which took up arms over Nagorno-Karabakh, a landlocked region in Azerbaijan populated by ethnic Armenians that had been autonomous from the state under the USSR but which is now globally recognized as part of Azerbaijan. Azeri President Ilham Aliyev has repeatedly vowed to take the region militarily.

Last week, the White House issued a statement condemning Azeri President Ilham Aliyev's pardon.

It added: "The United States is also requesting an explanation from Hungary regarding its decision to transfer Safarov to Azerbaijan."

The head of Azerbaijan's foreign relations, Novruz Mammadov, issued a statement accusing Armenia's leadership of "open support for terror" that emboldens groups like the Armenian Secret Army for the Liberation of Armenia (ASALA), which is seeking to re-establish the historical boundaries of Armenia, which include a large part of eastern Turkey as well as Nagorno-Karabakh and the land between the disputed region and the Armenian border.

Aliyev's decision to treat Safarov as a war hero has enraged the Armenian public. Public protests were staged this week in the Armenian capital, Yerevan, where Rasmussen visited on Tuesday.

NATO is urging both countries to resolve their conflict "through dialogue, compromise and cooperation," Rasmussen said.

The United Nations backed these statements on Thursday, but Azeri public sentiment appears to be on the side of its president and the convicted killer he pardoned.

"The extradition and pardoning of national army officer Ramil Safarov has filled us, young people, and indeed the entire nation with a sense of pride and joy," said one letter posted on the president's website that purported to be from a local youth club manager, according to the AFP.

Approximately 30,000 people were killed in the 1988-1994 war between the two countries. The countries fought a previous war over the issue from 1918 until the Sovet Union swallowed up both countries in 1922.