The lawyer of an Iranian-American journalist jailed in Iran for espionage said on Monday he would appeal the eight-year sentence next week and the judiciary chief ordered a 'quick and fair' handling of the case.

US-born freelance reporter Roxana Saberi was sentenced on charges of spying for the United States in a verdict that could complicate Washington's efforts for reconciliation with the Islamic Republic after three decades of mutual mistrust.

But in an intervention welcomed by her defence lawyer, Iranian President Mahmoud Ahmadinejad called on Sunday on Tehran's general prosecutor to ensure that the 31-year-old enjoys full legal rights to defend herself.

Analysts cautioned against seeing Saberi's case as a sign of Tehran rebuffing overtures by the new US administration of President Barack Obama, who has offered a new beginning of engagement if Iran 'unclenches its fist'.

Iran says it would welcome constructive talks with world powers on its disputed nuclear programme and other issues.

One Iranian political analyst, who declined to be named due to the sensitivity of the issue, said he expected Saberi's sentence to be commuted or reduced by a higher court.

Obama said on Sunday he was 'deeply concerned' for the safety of Saberi and urged Tehran to free her, saying he was confident she was not involved in spying.

Iran's Foreign Ministry spokesman said the United States should respect rulings issued by the Islamic state's courts, but that Saberi had the right to appeal.

'It is an international norm that one should respect the rulings issued by the court. I'm sure some American officials have also studied law,' Hassan Qashqavi told reporters.

The ISNA news agency quoted defence lawyer Abdolsamad Khorramshahi as saying he will next week lodge an appeal against the verdict on Saberi, who has worked for the BBC and US National Public Radio (NPR).

In a decree to Tehran's most senior court official, judiciary chief Ayatollah Mahmoud Hashemi Shahroudi 'emphasised the necessity of access to fair consideration of Roxana Saberi's case, especially at the appeals stage,' a statement said.

'Different dimensions of this case, including material and moral elements of the crime, must be considered at the appeals stage in a careful, quick and fair way,' the judiciary added.

US Secretary of State Hillary Clinton has said releasing Saberi, 31, would serve as a goodwill gesture.

Saberi, who is a citizen of both the United States and Iran, was arrested in January for working in Iran after her press credentials had expired.

Her father, Reza Saberi, told NPR on Saturday she had been coerced into statements that she later retracted.

Reporters Without Borders, the Paris-based media rights group, has called Saberi's conviction 'unjust under the Iranian criminal code' and said her lawyer was not with her when she appeared before the judges for the single hearing on April 13.

Washington cut ties with Iran shortly after the Islamic revolution in 1979, but Obama is seeking to engage it on a range of issues, including the nuclear dispute.

Iran says it wants to see a real switch in Washington's policies away from those of former President George W Bush, who led a drive to isolate the country because of nuclear work the West suspects has military aims, a charge Tehran denies.-Reuters