France says its 15,000 nationals in Ivory Coast should leave, as a "precaution", amid an ongoing crisis over a disputed presidential poll.
The man named as provisional prime minister has called for the use of force to remove incumbent Laurent Gbagbo, who is refusing to step down.
The UN says civil war could erupt because Mr Gbagbo is refusing to admit defeat and wants UN peacekeepers out.
Meanwhile, the World Bank said it had frozen its loans to Ivory Coast.
After a meeting in Paris with French President Nicolas Sarkozy, World Bank chief Robert Zoellick confirmed that the institution had stopped lending and disbursing funds, and that its office in Abidjan had closed.
"The World Bank and the African Development Bank have supported [Economic Community of West African States] Ecowas and the African Union, in sending the message to President Gbagbo that he has lost the election and needs to step down," a statement on the bank's website said.
"A peaceful and rapid resolution is critical both for the people of [Ivory Coast] and the region as a whole."
Provisional President Alassane Ouattara has also appealed to the West African Central Bank (BCEAO) to cut off Mr Gbagbo's access to Ivory Coast's deposits, making it impossible for him to pay civil servants and soldiers.
Speaking to a French TV station, PM-elect Guillaume Soro said international sanctions had failed to achieve their aim and called for more action to remove Mr Gbagbo.
"It is obvious that there is one solution left - that of force," he told the i-tele station, describing the situation as "very worrying".
Mr Gbagbo says the vote on 28 November, meant to unify a country split by war in 2002, was rigged in rebel areas that backed Mr Ouattara.
The country's Independent Electoral Commission ruled that Mr Ouattara had won, a decision later certified by the UN. The Constitutional Council said Mr Gbagbo had been elected, citing vote rigging in some areas.
Appealing to French nationals on Wednesday, Mr Baroin said they should leave "temporarily until the situation normalises".
Correspondents say there are fears that 10,000 UN personnel and other foreigners could be targeted as tensions increase.
Mr Ouattara and his supporters are currently holed up in the Golf Hotel in the main city, Abidjan, protected by 800 peacekeepers.
Mr Gbagbo has said his rival can leave but a blockade of the hotel remains, and no supplies or medicines are being allowed in.
At the weekend a spokeswoman for Mr Gbagbo warned the peacekeepers that they could be treated as rebels if they did not leave.
The UN rejected the call, and on Tuesday extended the mission's mandate by another six months.
The BBC's John James in Abidjan says the country is currently part of the Heavily Indebted Poor Countries programme but now looks unlikely to gain debt relief in 2011, contrary to previous forecasts.
Speaking on Tuesday, UN Secretary-General Ban Ki-moon said there was a "real risk" of a return to civil war in Ivory Coast.
"I am concerned that this disruption of life-support supplies for the mission and the Golf Hotel will put our peacekeepers in a critical situation in the coming days," he said.
"Facing this direct and unacceptable challenge to the legitimacy of the United Nations, the world community cannot stand by," he added.
He also revealed that the UN mission to the Ivory Coast (Unoci) had confirmed "mercenaries, including freelance former combatants from Liberia, have been recruited to target certain groups in the population", and that an arms embargo was being broken.
On Wednesday, the US said it was discussing with members of Ecowas the possibility of reinforcing the UN mission.
"We can't rule out that at some point in time [Mr Gbagbo] may challenge the presence of that force through force of his own," state department spokesman PJ Crowley said.
"We want to make sure that the UN has the capability to maintain peace and stability in [Ivory Coast] while this is being worked through."
Mr Gbagbo appeared on state TV on Tuesday for the first time since the election to restate his claim to be the country's legitimate leader.
He blamed his "opponent's refusal to submit to the law" for the unrest, which has seen at least 50 people killed, according to the UN.
He called for an international "evaluation committee" to examine the election process, but this was rejected by Mr Ouattara.
The European Union's foreign affairs chief, Baroness Catherine Ashton, also said the election result could "neither be submitted to any form of evaluation, nor be questioned".
"On the contrary, it is important that transfer of power takes place without delay and without preconditions," a statement said.
The election, delayed for five years, was supposed to reunify the world's largest cocoa producer, which was split between the government-controlled south and rebel-controlled north.