Speaking at a press conference, White House press secretary Sarah Huckabee Sanders blamed Corker, the Republican chairman of the Senate Foreign Relations Committee, for allegedly collaborating with Democrats in favor of the Iran nuclear deal under then-US President Barack Obama.
"Senator Corker worked with Nancy Pelosi and the Obama administration to pave the way for that and rolled out the red carpet for the Iran deal," Sanders said.
"He may have voted against the deal ultimately, but he not only allowed the deal to happen, he gave it credibility. I stand by my statement," Sanders added.
Corker's office was quick to release statement, which rejected Sanders' claims as "not true."
Sanders' remarks added fuel to the fire of the current war of words between Trump and Corker, which intensified earlier this week when the US President brushed aside Corker's allegations that his policies could lead to a Third World War.
Trump said that the current US administration is "on the right path" and that it was the previous US administrations that should be blamed for "a very big problem."
Last Sunday, Trump accused Corker of being "a negative voice in the way of our great agenda," as well as allegedly "begging" Trump to endorse him for re-election and not having "the guts."
Corker responded by saying that "it's a shame the White House has become an adult day care center."
The Senator has repeatedly criticized Trump's policies, including those related to the North Korean crisis and the Iran nuclear deal.
The Joint Comprehensive Plan of Action (JCPOA), also known as the Iran Nuclear Deal, was signed in July 2015 by Tehran the P5+1 group of nations comprising Russia, the US, China, France and Britain plus Germany after years of diplomatic work.
Trump called the JCPOA, negotiated under Obama's watch "an embarrassment" to the US during his speech to the UN General Assembly last month, and he has repeatedly slammed it during his presidential and election campaign.