UN chief weapons inspector Hans Blix said the question of war and peace now lay with the Iraqi government.
Mr Blix is in Cyprus en route to Iraq, along with International Atomic Energy Agency director Mohamed El Baradei and a 25-strong team of technical experts.
The Baghdad government, for its part, has promised full co-operation, and reaffirmed that it had developed no weapons of mass destruction since the last round of international inspections four years ago.
"We're on our way to a new chapter of inspections in Iraq," Mr Blix said on Sunday, during a joint news conference with Mr El Baradei at Cyprus's Larnaca airport.
When asked how sure he would be that Iraq was not concealing weapons, Mr El Baradei said: "We do not take 'no' for an answer. We have to verify a 'no' is actually a 'no'.
"This is an opportunity for peace. I hope Iraq will make full use of it," he said.
"It's an opportunity for Iraq to come back to be fully members of the international community and to eventually eliminate sanctions," he added.
Compliance
Meanwhile, Iraq's Deputy Prime Minister Tariq Aziz said his government was ready to comply fully with the arms inspectors.
"We will provide immediate access," he told London Weekend Television's Jonathan Dimbleby programme on Sunday.
"We have given instructions to all responsible people and many government areas to respond immediately to any request to enter their sites and inspect them."
But Mr Aziz added that inspectors should not think they could just walk into sites.
"When you go to a site, the site has a gate. The gate has to be opened and (the person) who opens the gate should know who is coming. This is common sense," he said.
Mr Aziz added that the results would expose as lies US charges that Iraq had weapons of mass destruction.
He warned that if the United States and Britain "wage a war against Iraq, consequences will be very bad to them and their friends in the region".
Logistics
Mr Blix said even a 30-minute delay in granting access to a suspect site would be regarded as a serious violation.
Mr Blix said the team travelling to Baghdad on Monday would first focus on working out logistics.
"There's a lot to organise," he said. "There are laboratories (to set up), a large number of jeeps, helicopters and a plane to be sorted out."
He said formal inspections start on 27 November, and he expected to have 100 inspectors in Iraq by the end of the year.
The first significant test is an 8 December deadline for Iraq to submit a full account of all its banned weapons programmes.
By 27 January next year, the inspectors must have given their first report to the UN Security Council.