The Maldives government Sunday told its critics to respect a controversial decision to jail the honeymoon islands' first-ever democratically-elected president for 13 years amid a growing global backlash over the verdict.

The US, European Union and regional power India have expressed concern over the jailing of Mohamed Nasheed on anti-terror charges for ordering the detention of a judge in 2012 when he was president.

President Abdulla Yameen said Nasheed had the right to appeal and urged international partners to engage with his government "constructively".

Yameen "calls on everyone to respect the verdict by the criminal court... against former president Nasheed," his office said in the first formal reaction to the court verdict on Friday night.

"The government calls on its international partners to engage constructively, based on mutual respect and dialogue in consolidating and strengthening democratic values and institutions in the country," the statement added.

Criminal charges against Nasheed were dropped last month only to be revived a few days later under a 1990 anti-terror law on the basis that his ordering the detention of a judge amounted to terrorism.

Rights group Amnesty International said the proceedings were "deeply flawed" and called the conviction "unsound", while Nasheed urged his supporters to take to the streets to protest a trial his party has said was "blatantly politicised".

"Rather than responding to international calls to strengthen the impartiality of the judiciary the government of the Maldives has proceeded with this sham trial for political reasons," said Amnesty's Asia-Pacific Director Richard Bennett.

Nasheed, meanwhile, was quoted by his office as saying: "I appeal to all of you today to stay courageous and strong, to confront the dictatorial power of this regime."

The 47-year-old is being held at the Dhoonidhoo prison on an island near the capital Male.

Corruption watchdog Transparency Maldives (TM) also said Nasheed had been denied adequate time to build a defence against the new charges of terrorism.

- Conflicts of interest -

TM noted what it said were multiple conflicts of interest, including two judges presiding over the trial having acted as witnesses for the prosecution.

A Maldivian representative at the United Nations denied that Nasheed's trail was politically motivated, but acknowledged that the emerging democracy needed help strengthening its institutions.

"The executive cannot interfere with the judiciary," Jeffrey Salim Waheed told AFP from UN headquarters in New York.

He admitted that the nation of 340,000 Sunni Muslims needed to heal the divisions that have riven the archipelago since the toppling of Nasheed in February 2012, four years into his five-year term.

"For the country to heal, all the institutions must be strengthened," he said. "We need help with that."

The trial came amid growing opposition to the government of Yameen who came to power in November 2013 in a run-off election. Nasheed won the first round of that poll, although without an outright majority.

Yameen's victory was due in part to his alliance with another eliminated presidential candidate, the business tycoon Qasim Ibrahim who has since teamed up with Nasheed.

If the conviction is affirmed by higher courts, it will effectively prevent Nasheed from running for president at the 2018 elections.

Night-time rallies and skirmishes with police have become routine in Male and it has damaged the atoll nation's image as an upmarket tourist paradise although the political unrest is not directly felt in the resort islands.

Nasheed came to power after building a pro-democracy movement with local and foreign support in opposition to the 30-year autocratic rule of Gayoom -- Yameen's half-brother.

He also built a reputation as a campaigner against climate change, holding an underwater cabinet meeting in 2009 to press the world to cap the carbon emissions that cause global warming and threaten low-lying countries such as the Maldives with extinction.