BuzzFeed has terminated an advertising deal with the Republican Party, saying presumptive presidential nominee Donald Trump is "hazardous to our health," the digital news group said Monday.

A memo from BuzzFeed chief executive Jonah Peretti reproduced on the news site said it had informed the Republican National Committee "that we would not accept Trump for President ads and that we would be terminating our agreement with them."

"The Trump campaign is directly opposed to the freedoms of our employees in the United States, and around the world, and in some cases, such as his proposed ban on international travel for Muslims, would make it impossible for our employees to do their jobs," Peretti said in the memo to staff.

"We certainly don't like to turn away revenue that funds all the important work we do across the company," Peretti said, adding that "in some cases, we must make business exceptions: we don't run cigarette ads because they are hazardous to our health, and we won't accept Trump ads for the exact same reason."

Although BuzzFeed did not estimate the amount of revenue lost, rival news organization Politico said the deal would be worth some $1.3 million.

BuzzFeed has directly expressed opposition to Trump before.

In December, editor-in-chief Ben Smith told staff in a memo that it was "entirely fair" to refer to Trump as a "mendacious racist" because "he's out there saying things that are false, and running an overtly anti-Muslim campaign."

The RNC said it had reserved space on a number of platforms including BuzzFeed to ensure it would get the best rates, but had no plans to advertise on the site.

"We never intended to use BuzzFeed," spokesman Sean Spicer said.

"Although it is ironic that they have not ruled out taking money from a candidate currently under investigation by the FBI," he added in a reference to an email probe of Democrat Hillary Clinton.