Malaysia has extended the amnesty for hundreds of thousands of illegal immigrants who had faced whipping and jail under a major crackdown.
Illegal workers are still expected to leave as soon as possible
Home Minister Azmi Khalid said this did not mean the crackdown would not go ahead, but that the migrants would be given one last chance to leave first.
He said the decision had been made on the request of tsunami-hit Indonesia, where most of the migrants are from.
Malaysia has blamed illegal migrants for rising crime in the country.
Some 380,000 migrants left Malaysia ahead of the latest deadline to avoid punishment, but at least 400,000 are believed to remain.
Mr Khalid said he had received a written request to delay the operation from Indonesian President Susilo Bambang Yudhoyono, who is worried that a major crackdown would flood the country with migrants when it is still struggling to recover from the December tsunami in the Indian Ocean.
"It may appear to most Malaysians that we have backtracked but we must put ourselves in Indonesia's shoes," Mr Khalid told a news conference.
More than 1m workers in Malaysia illegally, key to construction and other industries
Government has been cracking down since 2002
Ahead of latest deadline, 380,000 people left
But he stressed the operation had only been delayed, not scrapped.
"We will advise illegal immigrants rounded up in our operations to return to their countries of origin before we take legal actions against them," he told the Bernama news agency.
"But this does not mean we are not going to launch a crackdown against them," he said.
The original deadline expired at midnight on Monday (1600 GMT). It is not clear when the new amnesty will end.
Estimates have put the number of undocumented foreign workers in Malaysia at more than one million. They play an important role in the Malaysian workforce.
"There's something like a dark cloud hanging over migrant workers in Malaysia," Irene Fernandez, head of the Malaysian human rights organisation Tenaganita, told BBC news on Tuesday.
"There's been a total kind of mismanagement of this whole process," she said.