"We have to change our plan to move people out of tents to the end of June," Mangkusubroto told a news conference to update reconstruction efforts in Aceh province, the region hit hardest by the Indian Ocean tsunami on Dec. 26, 2004.

"We don't want to use timber coming from Aceh and we prefer to use timber from outside Indonesia. The only available sources of timber are from Africa, the rest ... will endanger protected forests," Mangkusubroto said without elaborating.

It was unclear where timber used so far had come from.

Some foreign aid groups that built some of the first wooden homes for survivors in Aceh were later told by conservation groups they had been sold illegal timber.

Illegal logging is rampant in Indonesia, the groups say.

On Dec 26, 2004, a magnitude 9.15 earthquake - the biggest in four decades - triggered a tsunami that left up to 232,000 people dead or missing in a dozen Indian Ocean nations, including nearly 170,000 in Aceh alone.

Half a million people were left homeless in Aceh, on the northern tip of Sumatra Island.

In a recent report, the Aceh reconstruction agency said 67,500 people were still in tents, many of which were becoming mouldy.

The agency aimed to build 120,000 permanent houses, with up to 78,000 completed this year, Mangkusubroto said.

Around 30,000 permanent houses have been built throughout Aceh and other nearby tsunami-hit areas of Indonesia so far.

Despite missing the deadline, Mangkusubroto defended the pace of the reconstruction, saying it was moving at "high speed". The rebuilding of homes was the top priority, he said.