Nikki Haley, the UN ambassador, has hit back at the
White House over claims she suffered "momentary confusion" over new
sanctions against
Russia, saying: "I don't get confused."
The diplomat was responding to comments by Larry Kudlow, the White House economic adviser.
On Sunday Ms Haley went on television to announce state that the US was preparing new sanctions against Russian companies.
The fresh measures would target "any sort of companies that were dealing with equipment related to [Syrian President Bashar al-] Assad and chemical weapons use" and send a "strong message" to Russian leaders, Ms Haley told CBS news.
The next day, the White House said they were still considering what action to take.
Ms Haley's on-screen comments angered President Donald Trump, according to the New York Times.
The row became public on Tuesday, when Mr Kudlow was pushed to clarify the administration's position on the sanctions.
Discussing Ms Haley's comments, he said: "She got ahead of the curve... There might have been some momentary confusion about that."
In an interview shortly afterwards, Ms Haley angrily responded to the comments telling Fox News: "With all due respect, I don't get confused."
Mr Kudlow later rowed back and called Ms Haley to apologise.
"I was wrong to say that," he told he New York Times.
"She was basically following what she thought was policy. The policy was changed and she wasn't told about it, so she was in a box."
The public spat has highlighted the underlying tension on foreign policy decisions within Mr Trump's senior ranks.
Ms Haley plays a significant role in determining the Trump administration's foreign policy, particularly since the Secretary of State Rex Tillerson was sacked last month.
Tensions between Russia and the US have risen since Mr Trump publicly rebuked the state for assisting Syrian President Bashar Assad and ordered American forces to carry out missile strikes in Syria with the UK and France.