LA PAZ, Bolivia (CNN) -- The prospect of more violence in Bolivia remained high Tuesday as negotiators continue to search for a solution to a crisis that has threatened to divide the country.
The central government of leftist President Evo Morales, Bolivia's first leader from an Indian majority centered in the western highlands, has been conducting talks with governors of largely white provinces in the east who want autonomy.
Both sides are trying to settle differences in the distribution of oil and gas revenue, autonomy for eastern states and Morales' plans for a constitution that would give more rights to indigenous Bolivians.
The talks began after clashes this month between supporters of the two sides killed at least 30 people.
On Tuesday, Morales plans to attend a U.N. assembly in New York that will draw heads of state from around the world. Before he left, he signed a proposal dealing with sharing gas revenue and a proposed new constitution and urged opposition governors to sign it, too. But Vice President Alvaro Garcia Linera expressed skepticism.
"There are signs to suspect that in reality there is no will to sign an agreement," he said.
Meanwhile, peasants who support Morales marched toward the city of Santa Cruz, an opposition stronghold, and said they were braced for a fight if the negotiations fizzle.
Hugo Fernandez, a peasant leader who supports Morales, joined pro-government demonstrators who were converging on Santa Cruz for a possible clash with pro-autonomy residents. He dismissed the talks.
"There is no dialogue," he said. "It's a trick. We don't believe anything they tell us."
Opposition figures such as Gov. Mario Cossio of the eastern Tarija state have said that they hope to strike a deal with the government.
Cossio said they hope "to build a national agreement that Bolivia needs, that the Bolivians want." The goal is to "give peace back to our country and give certainty to Bolivia," he said.
Differences about Bolivia's future have threatened to rend the country.
Peasant leader Julian Torrico said he and other Morales supporters will storm the eastern city of Santa Cruz if the talks do not yield progress. Watch as protesters threaten to take Bolivia's wealthiest city »
"We will go into Santa Cruz and respond with force because they have [marginalized] us and massacred us, so we will massacre them and we will take their land away from them," he said.
"The fight here is between poor and rich. The government of Evo Morales took power by a majority, and now these opposition governors don't want to let him govern."
On the other side of the divide stand people such as Anyelo Cespedes, president of the Santa Cruz Youth Union, which opposes Morales.
"We don't want a dictatorship or a communist regime," he said. "We have our way of life, and we don't want that changed."
The central government and eastern governors started negotiations last week -- talks that may offer one of the final chances to reverse Bolivia's slide toward violent instability, said analyst Gonzalo Chavez.
"This is probably one of the few opportunities that we're going to have to solve the problems of the country," he said.
Four of nine provinces in Bolivia have declared autonomy from the central government in referendums this year. Morales -- an ally of President Hugo Chavez of Venezuela and former President Fidel Castro of Cuba -- said the moves could cause Bolivia to disintegrate.
The eastern opposition leaders have long opposed a decision of the Morales government to divert some revenue from oil and gas produced in the region to pay for government programs for the elderly. They also have opposed his plans to revise the constitution to give greater rights to the indigenous majority.
The differences flared into violence this month, with opposition protesters occupying government buildings and energy installations.
Morales has said the opposition leaders are trying to overthrow the government. He expelled the U.S. ambassador, Philip Goldberg, on the grounds that the envoy urged anti-government protesters to get violent -- an assertion the U.S. denied.
"This is a coup in the past few days by the leaders of some provinces, with the takeover of some institutions, the sacking and robbery of some government institutions and attempts to assault the national police and the armed forces," Morales has said.
Opposition leaders said they merely want their demands met.
CNN's Karl Penhaul and Gloria Carrasco contributed to this report.