The United States has expressed mounting concern about a flurry of attacks on Iraqi bases used by US troops.
Iran on Monday accused the United States of dreaming up "imaginary enemies" after Washington warned there would be a stiff response if US interests in Iraq are attacked.
"When politicians want to absolve themselves of blame they always make up an imaginary enemy," Iranian government spokesman Ali Rabiei told a press conference.
"This is the American tradition - creating enemies and projecting blame on an enemy. I think America should review its policies in Iraq."
He added Washington's aim was "to intensify a psychological war" against Tehran, and that it was making accusations for which it has "presented no evidence".
If Washington went ahead with implementing its threats "it will receive a crushing ... response", Rabiei warned.
The United States has expressed mounting concern about a flurry of attacks on Iraqi bases used by US troops, several of which it has blamed on Iranian-backed Shiite paramilitary groups.
Since October 28, rockets have 10 times targeted areas where US soldiers and diplomats are based. The attacks have never been claimed.
US Secretary of State Mike Pompeo warned on Friday there would be a "decisive response" if American interests were harmed in Iraq - an ally of both Iran and the United States.
"We must... use this opportunity to remind Iran's leaders that any attacks by them, or their proxies of any identity, that harm Americans, our allies or our interests will be answered with a decisive US response," Pompeo said in a statement.
"Iran must respect the sovereignty of its neighbours and immediately cease its provision of lethal aid and support to third parties in Iraq and throughout the region," he said.
Tensions have been on the rise between the US and Iran, since US President Donald Trump last year decided to withdraw from a landmark 2015 nuclear accord agreed between Tehran and several world powers.