The U.S. Federal Trade Commission is prepared to break up major technology companies if necessary by undoing past mergers, Chairman Joe Simons said in an interview with Bloomberg published on Tuesday.

Simons said in the interview that breaking up a company is challenging, but could be the right remedy to rein in dominant companies and restore competition.

He is leading a broad review of the technology sector to see whether companies, including Facebook Inc, are harming competition.

Bloomberg quoted Simons as saying of breaking up companies, “If you have to, you do it.” He added, “It’s not ideal because it’s very messy. But if you have to you have to.”

Senator Elizabeth Warren has vowed to break up Amazon.com, Alphabet Inc’s Google and Facebook if elected U.S. president, to promote competition in the technology sector.