Mr Zelaya has postponed his return home until the deadline expires
The newly installed government in Honduras has rejected international calls to restore ousted President Manuel Zelaya to power.
The Organization of American States gave Honduras until the weekend to act or face suspension from the group.
Mr Zelaya has delayed his planned return home on Thursday.
An overnight curfew has been toughened to allow people to be held for 24 hours without charge, as protests both for and against Mr Zelaya continue.
The army ousted Mr Zelaya on Sunday over his plans for constitutional reform, which his critics said were aimed at prolonging his presidency.
Roberto Micheletti, the Speaker of Congress who was sworn in as interim president, said of the OAS deadline: "We can't negotiate anything.
"We can't reach an agreement because there are orders to capture the ex-President Zelaya here for crimes he committed when he was an official."
Troops guarded government buildings during pro- and anti-Zelaya protests
Mr Micheletti again denied that Mr Zelaya's removal amounted to a coup.
"The full Congress took a decision and decided to replace him, that's why it's called 'constitutional succession' and they chose me to replace Zelaya," he said.
The president's expulsion has been widely condemned by leaders ranging from US President Barack Obama to Mr Zelaya's regional allies, including Venezuelan President Hugo Chavez.
Mr Zelaya, in Panama for the inauguration of President Ricardo Martinelli, said: "I'm going to respect those 72 hours that the OAS asked for."
The US has suspended military co-operation with Honduras and says it will decide next week whether to cut aid.
Mr Zelaya's decision to postpone his return was described as "wise" by a senior Obama administration official quoted by Reuters news agency.
The World Bank and Inter-American Development Bank have cut new loans and some European countries have recalled their ambassadors.
The head of the OAS, Jose Miguel Insulza, condemned what he described as "an old-fashioned coup" in Honduras, after an emergency meeting of the regional grouping on Tuesday.
"We need to show clearly that military coups will not be accepted," he said.