By Emily Glazer and Michael C. Bender

The Trump campaign, known for its social media savvy, is hitting digital roadblocks.

Facebook's decision to remove Trump campaign political ads and posts last week, citing its policy against organized hate, surprised campaign officials. It added urgency to internal discussions about devising workaround plans if some of the world's largest social media companies continue to remove or block content from the campaign and President Trump, people familiar with the matter said.

The campaign is unlikely to pull advertising on Facebook, campaign officials said, since it can reach around 175 million U.S. users. The campaign has spent $19.6 million on Facebook ads so far this year. But the rebuke from the social media giant, following restrictions from Twitter Inc. and Snap Inc.'s Snapchat, has top campaign officials considering alternatives, such as moving to another, lesser known company, building their own platform or doubling down on efforts to move supporters to the campaign's smartphone app, according to people familiar with the discussions.

But there is disagreement internally over what -- if anything -- to do next, the people said. No other platforms offer the reach of Facebook or Twitter, and with about five months until Election Day, time is running out. The situation has been described internally as "code red," a person familiar with the matter said.

Still, while some content by Mr. Trump or the campaign has recently been flagged or taken down, nearly all gets through on social media outlets.

Trump campaign manager Brad Parscale and others in the campaign have talked for months about building up audiences on alternative platforms, including social media platform Parler, a person familiar with the conversations said. Parler describes itself as an unbiased social media platform focusing on free expression, according to its website.

"It's a great concern that Twitter clearly enforces its arbitrary rules in only one direction -- against conservatives generally and President Trump specifically," said Tim Murtaugh, the Trump campaign communications director.

Twitter has said its move last week was the first time it added the manipulated-media label to a Trump tweet, under a policy established earlier this year governing doctored images and audio.

Mr. Parscale, speaking Friday on Fox, said Facebook Chief Executive Mark Zuckerberg understands the importance of free speech. "He's had to placate certain portions of his staff, but if you look at other companies like Google and Twitter they...just say OK we'll do this, do this, do this, because they threatened walkouts."

When Facebook took down campaign content -- citing policy violations over the inclusion of an inverted red triangle image that Nazis used to designate political prisoners in concentration camps during World War II -- it stunned some in Trump campaign, the people said.

The Trump team reached out to Facebook about the move, asking questions about why it took down their posts and ads, people familiar with the matter said. Facebook responded to the Trump campaign, reiterating its decision to take down the posts and citing the policies the content violated, one of the people said.

Campaign officials also asked Facebook if the company was going to remove a similar symbol from its catalog of emojis, another person familiar with the matter said, which the campaign flagged publicly Thursday.

It isn't just Facebook. Twitter on Tuesday limited the spread of a tweet from Mr. Trump condemning an "Autonomous Zone" in Washington, D.C., that he said would be met with "serious force." Twitter said the tweet violated its policy against abusive behavior. Last week, the platform labeled one of Mr. Trump's tweets as "manipulated media" when his post included a doctored video.

The tech platforms, also including Alphabet Inc.'s Google, are increasingly squeezed between those pressing for more action to clean up hateful or misleading content on their platforms and those who argue that they already are interfering too much with free expression in ways that could reflect bias.

Before its takedown of Trump campaign content, Facebook's head of communications and policy, Nick Clegg, addressed some of the different perspectives among stakeholders on a call with media last week.

"The Trump administration is demanding that we stop or reduce censoring content and that we fact-check less materials," he said, according to a transcript of the call. "Civil rights groups and the Biden campaign are demanding that we censor and/or fact-check more. Policy makers are just going to have to decide what rules they want for campaigns and for the role of the Internet, and particularly at times of electoral campaigns."

The Trump campaign heavily relies on Facebook to reach new potential donors, engage with supporters and raise money. Mr. Trump's official Facebook page has roughly 30 million followers, compared with just 2.2 million for the page of the presumptive Democratic presidential nominee, former Vice President Joe Biden. Mr. Trump is also an avid Twitter user, tweeting about 50,000 times to his roughly 82 million followers, compared with Mr. Biden's 6.3 million followers.

The Trump campaign has also made a big push to boost its app downloads since it launched in April, people familiar with the efforts said. The app was designed to directly engage supporters while collecting data that could be used to boost donations, volunteer efforts and turnout on Election Day. Following stay-at-home orders during the coronavirus pandemic, the Trump campaign has used the app to stream its regular broadcasts and other content.

It also "gamifies" part of the app so users can earn points for actions like donating or getting friends to download the app, which could lead to discounts on campaign swag or even a photo with Mr. Trump, among other rewards. That ultimately helps the campaign since it encourages users to directly spread the app to family and friends who may be more inclined to download it and share their contact information if it is coming from a trusted source.

The Trump campaign owns content and distribution on the app rather than relying on a third-party platform and worrying about restrictions imposed on its activities, the people said.

Mr. Parscale has started to more publicly hint at the use of other platforms. On Thursday night, around when Twitter labeled Mr. Trump's tweet, Mr. Parscale tweeted: "Hey @twitter, your days are numbered" and linked to a post from him on Parler. Around the same time, White House social media director Dan Scavino, who sometimes operates Mr. Trump's Twitter feed, tweeted a link to his own Parler post, tagging the platform and #MAGA. A Twitter spokesman declined to comment on the posts.

Parler co-founder and Chief Executive John Matze said the platform has more than one million users, compared with about 100,000 around a year ago. "We are thrilled to see that support for Parler is growing and being utilized by anyone who seeks out and/or champions free and fair debate in a true public square," he said, adding that he has not heard from the Trump campaign since Messrs. Parscale and Scavino posted about Parler. "It is not Parler's job to weigh in on political matters. We believe in free speech and fair elections. Period."

Research firm eMarketer said it doesn't measure the user base of Parler, which was founded in 2018. By comparison, Facebook has 175.4 million U.S. users, Twitter has 53.5 million U.S. users and YouTube has 212.6 million U.S. viewers, according to eMarketer data as of February 2020.

Marshall Van Alstyne, a Boston University professor who researches social media firms' free speech policies, said the Trump administration has uniquely harnessed social media to generate attention.

He said that despite the recent curbs, social media platforms are both flooding users with information and "pushing responsibility onto users themselves for deciding what's true." He added: "That's becoming increasingly difficult to do."

Write to Emily Glazer at emily.glazer@wsj.com and Michael C. Bender at Mike.Bender@wsj.com