As the leaders of NATO nations gathered for a summit in Istanbul, de Hoop Scheffer was quoted by Italy's Il Sole 24 Ore daily, published on Sunday, as saying the alliance would limit its operations in Iraq to whatever was requested by the new government there.
The NATO members settled a dispute on Saturday over how to respond to a call from Iraq's incoming government for security forces training, averting a row before the Istanbul summit.
Diplomats said a positive response to Prime Minister Iyad Allawi's request was hammered out by envoys in Brussels on Friday. De Hoop Scheffer said in the interview with the newspaper he was optimistic the heads of government would sign the deal in Istanbul.
He said NATO must also remain committed to Afghanistan, keeping its promise to the government there.
"The international community in its entirety, not just NATO, cannot allow itself to see Afghanistan return to being a safe haven for terrorism," he said.
"The same goes for Iraq, which cannot go up in flames amid general indifference. Because the entire region would be destabilised," he said.
US President George Bush is eager to share the burden in Iraq and is under pressure in an election year to obtain more international support for Baghdad, whose interim government is due to be sworn in when the US-led occupation ends on 30 June.
Protestors in Istanbul insist
'USA get out of Middle-East'
But his administration has lowered its ambitions for NATO support, partly because France, Germany and other opponents of last year's invasion oppose an overt alliance role.
"NATO's new approach to crises does not mean that today we should say to Iraq what it should do," said de Hoop Scheffer. "The decisions must be made by the government in Baghdad, not by the Alliance's headquarters in Brussels."
Meanwhile, US Defence Secretary Donald Rumsfeld said on Sunday he expects leaders at the NATO meeting in Istanbul to strike a deal to allow NATO troops to train security forces in Iraq.
"We anticipate that at this summit, heads of state will end up agreeing that NATO will in fact have a role in training and equipping the Iraqi security forces," Rumsfeld told the BBC from Istanbul, where the summit will be held on Monday and Tuesday.
About 20,000 demonstrators, some chanting "USA get out of the Middle East!" have gathered on Sunday in an Istanbul square to protest the visit of Bush and the summit.