The Qatari investments challenges the USA administration, as both Turkey and the US are living a diplomatic dispute as Erdogan refused to give in to pressures from the U.S.to release 50-year-old evangelical pastor, Andrew Brunson, who Turkey accuses of aiding a coup attempt against Erdogan two years ago.
The U.S. has already doubled steel and aluminum tariffs on Turkey and slapped sanctions on two Cabinet ministers.
The decree said the move brought tariffs to 50 percent on imports of U.S. rice, 140 percent on hard alcoholic drinks like spirits, 60 percent on leaf tobacco and 60 percent on cosmetics.
Turkey's Vice President Fuat Oktay said on Twitter that the tariffs on certain products were increased "within the framework of the principle of reciprocity in retaliation for the conscious economic attacks by the United States".
Erdogan on Tuesday said Turkey would boycott USA electronic goods like iPhones, even though he has himself been photographed repeatedly using the product himself.
Turkish Finance Minister Berat Albayrak, who is Erdogan's son-in-law, and his Qatari counterpart Ali Sharif Al-Emadi were present at the talks in the capital Ankara.
In recent days, Qatari supporters of Turkey have begun a public campaign in Doha to change their riyals into lira in an attempt to shore up the plunging Turkish currency.
Targeting critics, Donald Trump threatens ex-officials' security clearances
And one of the individuals - Hayden - told Vox's Alex Ward that revoking his security clearance won't stop him from speaking out. After the briefing, former Obama staffer Ned Price tweeted that the White House was " seeking to revoke the First [Amendment ]".
The White House says "we won't forget" how Turkey has treated a detained American pastor, after a court rejected his appeal for release.
Erdogan has warned Turkey could seek alternative partners, pointing to Ankara's strong ties with Russia, Iran and China.
Erdogan thanked the emir and the people of Qatar for "standing by Turkey", the official Anadolu news agency reported.
Turkish President Tayyip Erdogan meets with Emir of Qatar Sheikh Tamim bin Hamad al-Thani in Ankara, Turkey August 15, 2018.
Turkish officials have also been keen to emphasise that Ankara wants to retain strong ties with Europe, which has also expressed deep unease with Trump's trade policies.
Qatar's royal court released a statement saying Al-Thani "issued directives that will see the State of Qatar to provide a host of economic projects, investments, and deposits" worth $15 billion to support the Turkish economy.