TEHRAN - Iranian Foreign Ministry spokesman Ramin Mehmanparast said Sunday that the verdict issued for two US hikers held in Iran was based on the "right judiciary procedure" and the "independence of (Iran's) judiciary system."

The Iranian court has followed the legal procedure in dealing with the illegal entry of Shane Bauer and Josh Fattal into the country and the espionage charges against them, the state IRIB TV quoted Mehmanparast as saying.

Tehran's Prosecutor General Abbas Jafari-Dolatabadi confirmed Sunday the earlier reports that each of the detained US hikers was sentenced to eight years in prison on the charges of illegal entry into the country's territory and espionage.

"Joshua Fattal and Shane Bauer each was sentenced to eight years of imprisonment," Jafari-Dolatabadi told a press conference.

The prosecutor said the two Americans have 20 days to appeal, but the case of their fellow Sarah Shourd, who was released last September on bail and returned home, is still open.

Sarah Shourd has said she will not attend the trial session in Iran, Jafari-Dolatabadi was quoted as saying by the official IRNA news agency.

According to the Iranian law, there is no barrier in trying Sarah Shourd and she would be tried in absentia, he added.

The fourth and last trial session to address the charges against the three hikers was held earlier this month in the Branch 15 of Tehran's Revolution Court.

Iranian Judiciary spokesman Gholam-Hossein Mohseni-Ejei said on Sunday that the two Americans' lawyer has been informed about the court's ruling.

US Secretary of State Hillary Clinton said Sunday that Washington was "deeply disappointed" by Iran's sentence of the two hikers.

In a statement issued by the US State Department, Clinton said the United States continued to call and work for the " immediate release" of the two Americans, saying that it was time for them to return home and reunite with their families.

"I joined President Obama and the people of the US in expressing our unflagging support for Shane, Joshua, Sarah and their families during this difficult time," she added in the statement.

The three US nationals were arrested in Iran on July 31, 2009 for illegally entering Iran's western border and were later charged with espionage. The US government considered the charges totally unfounded.

The female hiker Sarah Shourd, once jailed in Iran with the other two Americans, was released by Tehran's prosecutor in September 2010 on a bail of 500,000 US dollars due to her health situation.