TEGUCIGALPA The de facto government of Honduras denied entry on Sunday to an Organization of American States delegation and threatened to close Brazil's embassy, where ousted President Manuel Zelaya has taken refuge.
The group of OAS officials had hoped to help broker a solution to Honduras' political crisis but was turned back at Tegucigalpa's international airport, a move likely to further isolate the government headed by Roberto Micheletti.
Hours earlier, Brazilian President Luiz Inacio Lula da Silva said he would ignore a 10-day deadline set by Micheletti to decide what to do with Zelaya, who is holed up with his family and some supporters in Brazil's embassy in the capital.
"Brazil will not comply with an ultimatum from a government of coup mongers," Lula told reporters at a summit of African and South American leaders in Venezuela.
Lula also demanded an apology from Micheletti, who issued a harsh statement late on Saturday warning that his government would be forced to take action if Brazil does not define Zelaya's status soon.
Zelaya was overthrown in a military coup on June 28, but on Monday he returned from exile, sparking a tense standoff with the de facto civilian government that has promised to arrest him on charges of treason.
Brazil has said Zelaya can stay as long as necessary, but Micheletti told the South American heavyweight to either grant the deposed leftist political asylum or hand him over to Honduran authorities to be prosecuted.
"We urge the Brazilian government to define the status of Mr. Zelaya in a period of no more than 10 days," the government said in a statement. "If not, we will be obliged to take additional measures."
Carlos Lopez, the de facto government's foreign minister, said Brazil would lose its right to have an embassy in Honduras if it ignores the deadline. But he stressed that the government would respect the sovereignty of the compound and has no plans to storm the building to arrest Zelaya.
"There has been no discussion of raiding Brazil's compound," Lopez said at a news conference in Tegucigalpa where he faulted Brazil for escalating the crisis by agreeing to house Zelaya in its embassy.
"The Lula government is to blame," he added.
Since Monday, hundreds of soldiers and riot police have surrounded the embassy where protesters have mounted almost daily marches to demand Zelaya be reinstated.
"If they enter by force, they will be committing an act that contravenes all international norms," Lula said of the security forces outside the building.
ZELAYA URGES "FINAL OFFENSIVE"
Zelaya, a logging magnate who is rarely without his trademark cowboy hat, urged his followers to descend on the capital to pressure for his return.
"I call on you to mobilize throughout Honduras, and that everyone who can come to Tegucigalpa to fight in the final offensive," he said in a statement on local Radio Globo.
The United Nations Security Council on Friday condemned harassment of the Brazilian embassy. Brazilian officials say food and supplies have only occasionally been allowed in and troops have blasted the building with high-frequency sounds.
Zelaya upset conservative elites by allying himself with Venezuela's socialist President Hugo Chavez. He demands to be restored to power, but the de facto government says presidential elections in November will resolve the crisis.
The showdown in Honduras is shaping up as U.S. President Barack Obama's first diplomatic test in Latin America, a region where Washington's influence has waned in recent years.
Obama has cut some U.S. aid to Honduras since the coup and pushed for Zelaya's return, but several Latin American leaders say he has not done enough to broker a solution.
Brazil, which has sought to assert itself as a regional leader under Lula, has backed Zelaya from the outset but was reluctant to take a leading role in a crisis outside its traditional sphere of influence in South America.
Soldiers toppled Zelaya at gunpoint and sent him into exile in his pajamas after the Supreme Court ordered his arrest. His critics say he broke the law by pushing for constitutional reforms they saw as a bid change presidential term limits and extend his rule. Zelaya denies wanting to stay in power.
His return stoked tensions in Honduras, a coffee and textile producing nation. One man was shot and killed in a clash between police and Zelaya supporters last week as pressure mounted to let him return to office.
The United States, European Union and Organization of American States have urged dialogue to bring Zelaya back to office. But the Micheletti government insists he must face justice at home.
(Additional reporting by Frank Jack Daniel in Venezuela; Writing by Todd Benson; editing by Anthony Boadle and Philip Barbara)