The United States may not have to increase its force levels in Iraq but it has contingency plans in case the need arises, US Defence Secretary Donald Rumsfeld said on Sunday.
Rumsfeld also said that threats by Iraqi insurgents to behead three Turkish hostages will not delay Wednesday's formal handover of power to Iraq's interim government or disrupt the Nato summit in Istanbul.
"The real task of security is not to flood a country with more and more troops," he told BBC Television from Istanbul.
Rumsfeld said the US Army was making contingency plans for more troops, should commanders in Iraq request reinforcements to help Iraqi security forces deal with an upsurge of violence.
"That does not mean that we will necessarily need them, that means we will do the prudent planning," he added.
The United States has about 140,000 troops in Iraq joined by nearly 25,000 other foreign forces.
Other US defence officials have said the Army is preparing for any need for an additional 10,000 to 20,000 troops, although they have not been requested by American commanders in Iraq.
Rumsfeld told reporters later that insurgents in Iraq were increasingly attacking "soft" civilian targets and those from allied countries in an attempt to discourage other nations and to get them to withdraw troops or aid from Iraq.
PRAISE FOR ALLIES: Rumsfeld praised Turkey, Japan and South Korea for refusing to negotiate with hostage takers in Iraq and said a 72-hour deadline set for the beheading of three Turkish civilians was aimed at disrupting a two-day summit of alliance leaders.
"Will it work? I think not ... It will not be effective," he said.
The United States previously questioned a decision by Spain to withdraw its troops from Iraq after a deadly train bombing in Madrid.
"I think you'll find that there may from time to time be some country that decides that they are going to change their approach," Rumsfeld told reporters.
"But I think, overwhelmingly, people understand that it is not wise to allow yourself to be terrorised...Once you start down that road, it's a dead end."