The announcement comes hours after the KRG parliament voted to hold the poll next week despite opposition from the central government and Iraq's neighbors.
Instead of pursuing the vote, the KRG should begin "serious and sustained dialogue" with Iraq's central government, White House spokeswoman Sarah Huckabee Sanders said in a statement.
KRG President Masoud Barzani said Thursday he could consider an offer to delay the vote.
The non-binding referendum is planned to see residents in provinces controlled by the KRG vote on independence from Baghdad on Sept. 25.
"The referendum is distracting from efforts to defeat ISIS and stabilize the liberated areas," she said. "Holding the referendum in disputed areas is particularly provocative and destabilizing."
The oil-rich province of Kirkuk is among the contested areas that the vote is planned to take in.
The Iraqi government believes that holding the referendum would violate the terms of the country's constitution.
Turkey and Iran, too, rejects it, saying the region’s stability depends on the unity of Iraq and the maintenance of its territorial integrity.
While Washington has voiced concern that the poll could serve as a “distraction” from other pressing regional issues, especially the fight against terrorism and the stabilization of post-ISIL Iraq, many experts believe those in favour of creating an Independent Kurdish state count on US support via Israel, the only regional country that has supported the creation of an independent Kurdistan in northern Iraq because the US open support to independence of kurdish region will require a major redefinition of its relationship with Baghdad and also the US will not be able to sustain its support for an independent Kurdish state without the support of some of its regional allies, especially Turkey which opposes the creation of an independent Kurdistan.
AA/MNA