The interim government that sent Manuel Zelaya into exile vows to arrest the president if he sets foot in Honduras, and imposed a 6 p.m. to 6 a.m. curfew along border areas.
Zelaya said he would make a second bid to return home on Saturday, saying U.S.-backed mediation efforts had broken down.
The 56-year-old ousted president, wearing a black leather vest and his trademark white cowboy hat, drove a jeep from the Nicaraguan capital to the northern town of Esteli, about 25 miles south of the Honduran border.
Accompanied by Venezuelan Foreign Minister Nicolas Maduro, Zelaya went inside a hotel that shut its black gates to dozens of reporters who had followed the ousted president on his journey from Managua. He said he would spend Friday planning his return home.
During the trip, smatterings of supporters gathered by the highway, setting off fireworks, chanting Zelaya's name and waving the red-and-black flags of Nicaragua's leftist Sandinista party.
It was unclear exactly how Zelaya was going to enter Honduras - spokesman Allan Fajardo said he could travel by air, sea, or land from any of three neighboring countries, Nicaragua, Guatemala and El Salvador. He said Zelaya would be accompanied by family, supporters and journalists.
Zelaya said he hoped soldiers would stand down when they see him return.
"I think the guns will be lowered when they see their people and their president," he said at a news conference at the Honduran Embassy in Managua shortly before leaving.
All governments in the Western Hemisphere have condemned the coup, in which soldiers acting on orders from Congress and the Supreme Court arrested Zelaya and flew him into exile. Nations on both sides of the political spectrum say Zelaya's return to power is crucial to the region's stability.
Latin America expert Vicki Gass said that if Zelaya's opponents succeed in driving him from power, it could have a ripple effect in a region where left-leaning elected governments are challenging elites that have ruled many countries for decades.
"Coups could then happen in Peru, where President (Alan) Garcia has a very low approval rating, or in Argentina or in Guatemala," said Gass, an analyst at the Washington Office on Latin America which promotes human rights and democracy.
Zelaya said the mediation efforts, led by Costa Rican President Oscar Arias, failed after representatives of the interim government flatly rejected the possibility that he might return to finish his presidential term, which ends in January 2010. They say they cannot overturn a Supreme Court ruling forbidding Zelaya's reinstatement.
But Jose Miguel Insulza, secretary-general of the Organization of American States, held out hope that the two sides might still reach a settlement - and called Zelaya's attempt to return without an agreement "hasty."
"He has always wanted to return to his country, but it's important to make an effort to avoid a likely confrontation," Insulza said.
He said that neither delegation had officially responded to Arias' proposal, which calls for Zelaya's reinstatement, amnesty for the coup leaders and early elections.
The United States warned of tough sanctions against Honduras if Zelaya is not reinstated, but also said Thursday it does not support Zelaya's plan to return on his own.
"Any step that would add to the risk of violence in Honduras or in the area, we think would be unwise," State Department spokesman P.J. Crowley said in Washington.
Zelaya dismissed the concerns of Insulza and the U.S., saying he waited nearly two weeks for the negotiations in Costa Rica to restore him to power. "Defending our rights is not an act of violence ... we are going to seek dialogue," he said.
In Honduras, Zelaya supporters turned up the pressure, blocking roads throughout the country Thursday and occupying several government buildings in peaceful protests.
The Honduran military thwarted Zelaya's first attempt to return home July 5 by blocking the runway at the airport in the capital, Tegucigalpa. The flight sparked clashes between Zelaya's supporters and security forces in which at least one protester was killed.
Lorena Calix, a spokeswoman for Honduras' national police, said officers were ready to detain Zelaya if he tries again to come home.
"When he comes to Honduras, we have to execute the arrest warrant," she said
The Honduran military said it would not be responsible for Zelaya's security if he returns, responding to the ousted president's warning earlier this week that he would blame military chief Gen. Romeo Vasquez "if something happens to me on route to Honduras."
The Defense Ministry suggested Zelaya might stage an assassination attempt on himself to blame Vasquez.
"We cannot be responsible for the security of people who, to foment general violence in the country, are capable of having their own sympathizers attack them," the ministry said in statement late Thursday.
Honduras' Supreme Court ordered Zelaya's arrest before the June 28 coup, ruling his effort to hold a referendum on whether to form a constitutional assembly was illegal. The military decided to send Zelaya into exile instead - a move that military lawyers themselves have called illegal but necessary.
Zelaya's opponents, who objected to his populist and socialist policies, have argued the president was trying to change the constitution to extend his term. Zelaya denies that.
If he is arrested, Zelaya faces four charges of violating governmental order, treason and abusing and usurping power that could bring 43 years behind bars. Prosecutors say they are investigating a raft of other allegations ranging from misappropriation of public funds to drug smuggling - accusations Zelaya says are purely political.