US troops totalling about 3000 have been hurriedly despatched to the Middle East.
They are to strengthen the number of American soldiers who are already stationed in the turbulent region.
This is part of ongoing efforts by the Trump administration to protect US interests threatened by escalating tension.
The Iraqi parliament overwhelmingly voted earlier for the withdrawal of all foreign troops from Iraqi soil, with Washington expressing serious concern over the decision.
Anxiety has been mounting in the Middle East since the killing of Soleimani in Bahdad, with European powers including Britain, Germany and France urging the United States and Iran to de-escalate the conflict.
While Britain believes the escalation of the crisis would not be in anyone’s interest, Germany and France appealed to Iran not to dump existing agreements entered into out of frustration over the US action.
Friday, President Trump ordered the killing of Soleimani seen as Iran’s number two man who was on a mission in Iraq.
Iran has vowed harsh retaliation, saying it would limit its response to attacks on American military sites.
Mike Pompeo, the US Secretary of State warned Washington would launch fresh attacks should Iran retaliate.
He said the world was more at peace as a result of the attack launched by America while a Military Adviser to Iran’s Supreme Leader, Hossein Dehghan stressed his country would strike a mortal blow at America that it considers proportionate.
Meanwhile, Iran has announced it is no longer bound by the agreement entered into with the United States and other World powers.
That agreement had allowed inspectors to visit Iranian nuclear sites to prevent nuclear enrichment.
On its part, Washington is threatening further sanctions and attacks on 52 Iranian sites as disagreements deepen.
Back in the United States, a row is gradually developing between Republicans and Democrats over the conduct of the attack by the Trump government.
Democrats are insisting they were not notified by the White House before US personnel went into action in the Middle East.
There is however evidence that a handful of top Republicans were put in the picture before the secret mission was launched.