ABIDJAN, Ivory Coast — Room for a peaceful resolution dwindled here as both men who claim to be president hardened their positions amid increasing accounts of political killings and abductions.

Nearly 200 people have been killed in Ivory Coast political violence that must be halted and fully investigated, the United States told the U.N. Human Rights Council on Thursday.

U.N. experts and many others agree that the Ivory Coast is edging closer to a return to the civil war that split the country in 2002. Many Abidjan residents are fearful that Ivory Coast is moving closer to armed conflict.

"War is inevitable. We have to go through a serious confrontation to liberate Ivorians once and for all," said Pierre Noel, an Abidjan-based television producer.

A top opposition figure has called for the international community to use force to oust Laurent Gbagbo from the presidency after the disputed election, though others urge all possible efforts at negotiation must be pursued.

"What we need is a real discussion between the two parties to assure that no more blood is spilled," said local restaurant waiter Beranger Kouassi.

The United States and the United Nations have increased pressure on incumbent Laurent Gbagbo to step down from power. Gbagbo, 65, lost the Nov 28 runoff election but refuses to leave office. Challenger Alassane Ouattara, 68, won the vote and is attempting to run the country from the Golf Hotel in downtown Abidjan.

The United States is looking at ways to strengthen the 9,000 United Nations troops currently in Ivory Coast. The U.S. is discussing ways to increase pressure on Gbagbo with neighboring African countries and France, the former colonial power, said U.S. State Department spokesman P.J. Crowley in Washington on Wednesday.

But Gbagbo is defiant. "I'm the president of Ivory Coast,” he said on state broadcasting Tuesday night in his first address to the nation since he had himself sworn in as president earlier this month.

Gbagbo railed against the international recognition of his opponent's victory.

“It's clear that those results are null and void," he said on state television on Tuesday night. "The international community has declared war on Ivory Coast. This is not acceptable and this will not be accepted."

Gbagbo has the support of the army and police. He is also using foreign mercenaries from Liberia and possibly Angola, according to reports by Amnesty International and other human rights experts.

Meanwhile Ouattara's prime minister called for force to be used to bring Gbagbo down. "It is obvious that the only solution to the crisis is the use of force," said Guillaume Soro. "I ask the U.N. Security Council, European Union and ECOWAS (the West African eocnomic community) to consider the use of force."

Fear has gripped ordinary Ivorians who report nightly killings and abductions by Gbagbo's militia. Numerous Abidjan residents report that truckloads of armed men drive through the streets at night, targeting homes of Ouattara supporters. At least 50 have been killed and more are missing, according to U.N. officials.

Neighborhoods have set up their own security system by setting up makeshift roadblocks. Housewifes bang pots and children blow whistles to alert others when they see the Gbagbo militia approaching.

The room for a negotiated compromise is dwindling, according to analysts.

"The question is whether the international community can muster the political will to master this situation very quickly," said Peter Pham, senior vice president at the National Committee on American Foreign Policy. "Absent a major attrocity — a headline-grabbing, conscience-shocking event over the holidays — I don't see an international consensus being mustered for military intervention," he said.

"If there's going to be any activity, it's going to have to be in the next two or three weeks. After that is Sudan's referendum," said Pham. "If Gbagbo can manage to hold out that long, he can count on the fact that the international community won't have the stomach for two major situations at once."

One pressure point that hasn't yet been explored, short of military intervention, would be a cocoa embargo, which could have a devestating effect on Ivory Coast, the world's largest producer. But European and American business interests could be severely damaged if their access to 40 percent of world supply of cocoa was cut off. This option, Pham said, "isn't even on the table.

In Washington, the State Department was clear that Gbagbo should leave power.

"President Gbagbo must accept the results of the election," said U.S. State Department spokesman P.J. Crowley. "From our standpoint this is not negotiable." The U.S. joined the EU in imposing travel sanctions on Gbagbo and his closest associates and is considering further steps such as financial sanctions.

The World Bank Wednesday froze all finance to Gbagbo.

Ouattara is supported by nearly unanimous international support from foreign governments and multinational institutions. Gbagbo, however, remains in control on the ground.

United Nations Secretary-General Ban Ki-moon warned of a real possibility of civil war on Tuesday. He said that since the contested elections Ivory Coast has seen a proliferation of human rights abuses including kidnappings, arbitrary detentions and extra-judicial killings.

The U.N. certified Ouattara's election victory win, but Gbagbo had Ivory Coast's Constitutional Council throw out more than half a million votes from Ouattara strongholds and declare him the winner.

The U.N. then called on Gbagbo to step down and respect the democratically elected winner of the election. But Gbagbo has adamantly refused to move out of the presidential palace. Instead he has named a prime minister and a cabinet and has started to govern as if it were business as usual.

The situation on the ground in Abidjan and across the country remains tense. The U.N. refugee body has already recorded 6,000 refugees who have fled to neighboring Guinea and Liberia and said they expect 30,000 to arrive in the coming weeks.

Reports of Liberian mercenaries working for Gbagbo were also confirmed by the U.N. this week. Witnesses described English-speaking soliders wearing Gbagbo's uniform during a pro-Ouattara demonstration last week. The pro-Gbagbo forces opened fire on the crowd in several instances killing as many as 30 people, according to some estimates.

France, Canada and Germany have called on all their citizens to leave Ivory Coast and many journalists have fled their homes, sleeping at the office, or in other safe locations.

Gbagbo called on the U.N. peacekeeping force of 9,000 troops to pull out of Ivory Coast over the weekend, accusing them of arming the rebel army allied with Ouattara and providing them with sensitive information.

He charged that the U.N. troops had overstepped the bounds of their mandate and had violated their neutrality and so therefore had to leave Ivory Coast.

But the U.N. fired back on Monday, extending its mission another six months and reiterating reports of human rights abuses and threats of international prosecution against Gbagbo and his entourage.

Gbagbo is also facing financial pressure, as efforts to cut off international funds have begun to bite.

The World Bank, the African Development Bank and the West African economic bloc known as ECOWAS have all suspended any funding to Gbagbo's government.

Ouattara's camp is also working on cutting him off from the state treasury. Ivory Coast shares a common central bank, called the BCEAO, with seven other Francophone west African countries, and Ouattara wrote to ask them to only grant access to his government, as it is internationally recognized.

An apolitical organization, the BCEAO has been sitting on the fence. It has not responded to Ouattara's request and a source at the bank, who asked to remain anonymous because he is not permitted to talk with the media, said that they are hoping the situation will resolve itself to avoid having to pick sides.

Tensions are high at the Golf Hotel, in central Abidjan, where Ouattara and his government is holed up and surrounded by a protective guard of 800 U.N. peacekeepers. Gbabgo's forces blockaded the hotel for five days, not permitting deliveries of food, water or medicine.

But Gbagbo extended an olive branch during his Tuesday speech, when he said deliveries of essentials could resumed. He also called on Ouattara's people to leave the hotel.

“No one will stop you,” he said, “you're free to leave.”

While deliveries of the essentials resumed on Wednesday, no one in Ouattara's camp ventured out from behind the razor wire, afraid of a trap.

Ouattara adviser Amadou Coulibaly, reached by phone, said that the Ouattara camp is suspicious of Gbagbo: “Mice don't trust smiling cats.”