President Trump's reelection campaign says it was prepared to spend more than $10 million on Twitter ads before the social network abruptly made "a mistake" and banned paid political content.

"We probably would have spent seven figures, potentially eight figures," a senior campaign official told reporters Thursday on a conference call for political journalists.

Twitter announced the political ad ban on Wednesday. CEO Jack Dorsey said in a tweet, "We believe political message reach should be earned, not bought."

The senior campaign official said that Trump "does a pretty good job of communicating a message on Twitter" and has demonstrated a "marketing efficiency that we've never seen in politics."

The ban on political ads on Trump's favored platform won't meaningfully affect the 2020 campaign, the senior official argued.

"The Facebooks and Googles of the world, they get the majority of the dollars [for online ads]. But for us, we have a very multi-channel approach," he said. "[We] never love when a channel, a pipe is turned off because that eliminates the opportunity to run observations against it."

The official argued the Twitter decision would be bad for business and for transparency but expressed confidence in Facebook CEO Mark Zuckerberg not following course.

[Also read: Facebook employees oppose company's political ad policy]

"I think Zuckerberg has made some good points about political speech," he said.

"I think it's a mistake by Twitter to walk away from revenue for their platform, and their shareholders, and their staff," the Trump campaign official said. "The worst side of it is they are basically saying they are not going to review political ads and they're just going to turn them off ... to me that sounds like we just won't know what is going on. Rather than have more transparency — which I think everyone is in favor of that — we are going to have less, so I think it's kind of a bad move for that reason."

The official added, however, that far fewer people use Twitter than Facebook.

"Twitter is a platform where less than 9% of the U.S. population is daily users," he told the call. "Frankly, it is just a lot of us who are on Twitter."