Maldivian authorities have already turned down requests by international media to cover the elections
The Maldives opposition has accused President Abdulla Yameen of covering up his attempt to "steal" this month's elections by denying access to foreign media.
The United States, the European Union and others have expressed alarm over the political situation in the Indian Ocean archipelago. Yameen's main rivals are either behind bars or in exile.
The opposition alliance hoping to unseat him on September 23 said late Wednesday that the government had tightened already stringent visa requirements for foreign journalists wanting to cover the vote.
"The visa measures are a deliberate attempt to restrict foreign journalists from travelling to the Maldives for the election, thus reducing independent scrutiny of the vote and President Yameen's likely attempts to steal it," the opposition said.
"In this regard, the measures should be viewed as a pre-emptive cover-up of planned electoral fraud," it said in a statement.
Conditions for journalists obtaining visas include naming a local sponsor who will be held responsible for any reporting deemed unacceptable.
Maldivian authorities have already turned down requests by international media to cover the elections.
The main opposition candidate, Ibrahim Mohamed Solih, told reporters in Colombo late last month that he did not expect a free and fair election, but was confident that voters would come out against the government.
Solih is endorsed by former president Mohamed Nasheed, who is in self-imposed exile himself after being handed a "terrorism" conviction and a 13-year jail term in 2015.
The United Nations has described Nasheed's trial, which disqualified him from running in the election, as politically motivated.
The country of 340,000 people popular with well-heeled foreign tourists has been on edge since Yameen imposed a 45-day state of emergency in February in order, his critics say, to prevent efforts to impeach him.
In the last election in 2013, the Supreme Court annulled the results of the first round of voting when Nasheed was in the lead.
The subsequent vote was then twice delayed, allowing Yameen time to forge alliances that helped him narrowly win the contested run-off.