This latest DA demand is one of a series of rows within the Government of National Unity that have threatened its survival, but the junior partner has yet to pull the plug on its involvement in the coalition.
The DA, in its ultimatum to Ramaphosa, accused the president of a "flagrant double standard" and called on him to fire ministers and deputies in his executive accused of wrongdoing.
Whitfield's removal was confirmed to several local news outlets, including News24, by the president's spokesperson Vincent Magwenya. No reason was given for the decision but Magwenya denied speculation that a cabinet reshuffle was in the works.
Cabinet reshuffles are often used to quietly remove officials who have been under criticism from the executive.
DA leader John Steenhuisen spoke in parliament about the sacking calling it a "calculated assault" on the DA and a "flagrant double standard".
"While a DA minister is removed for not getting a response to seeking permission to travel, there are members in the cabinet who are implicated in [corruption]. Perhaps there is something deeper at play here.
"Should the ANC fail to meet our ultimatum, all bets are off and the consequences will be theirs to bear," Steenhuisen added.
Whitfield also broke his silence on the issue in an interview with South African public broadcaster SABC on Thursday evening.
He said no reason or "formal explanation" for his axing was given in the letter he received.
He acknowledged that his trip to the US, taken at the behest of his party, was not approved by the president, despite the fact that he submitted his request two weeks prior to his departure.
"I simply took silence as consent and perhaps that was an error in judgment on my part," he conceded.
He echoed Steenhuisen's remarks that there may be another motive behind his firing, labelling it "premature and an unnecessary provocation".
"I just don't see a situation in which the DA can continue to operate in the GNU in the way we have. There are a number of options at our disposal [and] leaving the GNU is one of them,"
he told the SABC.
The BBC has asked the president's spokesperson to respond to the allegations and threat but has yet to receive a response.
The DA is one of the 10 parties that formed the GNU, led by Ramaphosa's African National Congress (ANC), after no party emerged as the clear winner in the 2024 general election.
Relations between the two biggest partners have been strained since the government was formed as the duo disagreed over several key issues. Tensions reached a boiling point earlier this year when the DA refused to support a crucial vote on the national budget in parliament.
The ANC then accused the DA of "complete betrayal" by breaking ranks with its partners in the GNU.