President Donald Trump said tariffs have bolstered the U.S. bargaining position while cost increases to consumers have been negligible and warned of more levies as prospective trade talks with China appeared in doubt.

“Tariffs have put the U.S. in a very strong bargaining position, with Billions of Dollars, and Jobs, flowing into our Country - and yet cost increases have thus far been almost unnoticeable,” Trump said on Twitter Monday. “If countries will not make fair deals with us, they will be ‘Tariffed!’”

Trump’s tweet came as CNBC reported a senior administration official said the U.S. is ready to go with $200 billion in additional tariffs on Chinese goods and may announce them as soon as Monday. Beijing will be forced to retaliate if U.S. rolls out new tariffs against the country, Chinese Foreign Ministry spokesman Geng Shuang was cited by Huanqiu.com as saying.

Trump also touted the benefits his 25 percent tariffs on steel imports have had so far on U.S. industry, as some companies have deployed promotional campaigns in support of those measures targeting voters in iron- and steel-producing states. Opponents have said the import barriers may raise costs, lower earnings or force employers to dismiss workers or move operations offshore.

“Our Steel Industry is the talk of the World. It has been given new life, and is thriving. Billions of Dollars is being spent on new plants all around the country!” Trump said in another tweet Monday.

Conflicting messages coming from the Trump administration on tariffs amid the U.S. trade war with China could sink prospective negotiations between the two nations before they begin, damaging prospects for a resolution to the growing dispute.

Trump has been telling aides to proceed with additional tariffs on Chinese products, but the Chinese government is considering declining the offer of talks, according to a Wall Street Journal report, which cited officials with knowledge of the discussions. Beijing last week welcomed the invitation to meet with U.S. Treasury Secretary Steven Mnuchin, an offer which was then undermined by a tweet from the president.

The lack of unity within the U.S. administration on trade isn’t new—Chinese and American officials have held a series of talks over the dispute, and reached at least one agreement which was subsequently abandoned by the president. The lack of progress and collapse of that deal have made future negotiations more difficult, as it’s unclear who speaks for the U.S. administration and there’s a lack of confidence that any deal will be honored.