Abidjan, Ivory Coast (CNN) -- The tug-of-war between the two men who claim the presidency of the Ivory Coast intensified Wednesday.
Soro Guillaume, who was picked by Alassane Ouattara to be prime minister in his government, said on Wednesday that the international community should use force to remove incumbent President Laurent Gbagbo from power.
The country's Independent Electoral Commission said Ouattara won a November 28 runoff election, but its Constitutional Council invalidated those results and declared Gbagbo the winner.
The United Nations, the African Union and other international and regional bodies recognize Ouattara as the victor, but Gbagbo has declined to step down.
A United Nations credentialing commission added pressure by approving on Wednesday a diplomatic maneuver that would further isolate the government of Gbagbo. The commission agreed to back a new ambassador to the body appointed by Ouattara.
U.S. State Department spokesman P.J. Crowley on Wednesday said that the United States and other countries were discussing with African nations the possibility of augmenting the existing U.N. force in the Ivory Coast. However, he said it was unclear what a U.S. contribution could look like, whether it be forces of logistical support or something more indirect. Right now, these are just ideas, Crowley said.
The World Bank on Wednesday said it has halted lending and disbursing funds to the Ivory Coast and that the agency's office in the West African country has been closed.
The agency said it and the African Development Bank have backed the AU and the Economic Community of West African States "in sending the message to Gbagbo that he lost the elections and he needs to step down."
"A peaceful and rapid resolution is critical" for Ivorians and the region, the bank said.
Meanwhile, France has become the latest Western country to warn its citizens of danger in the Ivory Coast.
French citizens in the West African nation should leave if possible, a government spokesman, Francois Baroin, said Wednesday.
The United States and United Kingdom also have warned their citizens of possible violence in the Ivory Coast, where up to 50 people are said to have been killed amid a political stalemate after a disputed presidential election.
The U.S. State Department ordered nonemergency personnel and family members this week to leave the country. It also warned U.S. citizens against traveling to the Ivory Coast, a former French colony of about 19 million people.
The UK Foreign Office also had advised British citizens to avoid travel to the Ivory Coast and, for those already there, to leave the country unless they "have a pressing reason to remain."
On Tuesday, U.N. Secretary-General Ban Ki-moon warned that the country risks a return to civil war
"In the past week, there has been an alarming increase in the use of intimidation by elements of the national security forces loyal to Mr. Gbagbo against the civilian population, and in particular against supporters of President-elect Ouattara," he said.
"The tactics include abductions and killings and the propagation of hate speech through the state broadcasting corporation," he continued. "There is a real risk of a return to civil war."
Gbagbo struck a defiant tone in a Tuesday speech, declaring, "I am the president." He stressed he is the legitimate winner of the election, but said he would be willing to welcome an international committee to review the results to avoid any further violence.
"I don't want any more bloodshed. I don't want any more war," he said.
U.N. peacekeeping chief Alain Le Roy referred to Gbagbo's remarks when he spoke to reporters in New York.
"Mr. Gbagbo has been very clear. He wants no violence, no more blood," Le Roy said. "So all the forces loyal to him should stop immediately provocation, instigating violence, violation of human rights and provoking" U.N. peacekeepers in the country.
Le Roy said Gbagbo's allies have been handing out rifles to members of a "Young Patriots" group, and mercenaries from Liberia and Angola have been hired "to provoke" civilians and U.N. peacekeepers.
Amnesty International, citing eyewitnesses, has said that it has heard an increasing number of stories of people arrested or otherwise taken by gunmen, often with the cooperation of security forces.
"It is clear that more and more people are being illegally detained by security forces or armed militiamen, and we fear that many of them may have been killed or have disappeared," Salvatore Sagues, Amnesty International's West Africa researcher, said in a written statement.
The U.N. Security Council has extended its peacekeepers' mission in Ivory Coast through June 30, despite an expulsion order by Gbagbo. The Gbagbo government accuses the United Nations of providing military and logistical support to former rebels who are backers of Ouattara -- a charge Ban denied.
CNN's Aliza Kassim and Eric Agnero contributed to this report.