Erdogan on the eve of the meeting said it was up to Brussels to decide if it wanted Turkey as a member of the bloc.
Juncker, who heads the European Commission, and Tusk, who heads the European Council of 28 EU member state leaders, met the Turkish leader ahead of a NATO summit in Brussels.
Tusk greeted Erdogan at EU headquarters, but neither men spoke during a brief and cordial handshake for photographers.
"EU and Turkey must and will work together," a spokesman for Juncker said in a tweet as talks began.
In heated remarks, Erdogan on the eve of the meeting said it was up to Brussels to decide if it wanted Turkey as a member of the bloc.
Speaking to reporters before leaving for Brussels, Erdogan said Turkey was not prepared to behave like a "beggar" to gain membership.
Relations between the bloc and Ankara soured after a failed coup attempt in July, and worsened further during the campaign for the April 16 referendum on strengthening Erdogan's powers.
In the run-up to the referendum -- which he narrowly won -- Erdogan had mooted reimposing the death penalty in Turkey, a move that would automatically end its EU bid.
Earlier this month, Erdogan told Brussels it had no other option than to open new "chapters", or policy areas, in Turkey's long-stalled accession talks which began in 2005.
Most EU states -- led by Germany -- officially oppose freezing accession talks with Turkey with only Austria openly backing a halt to the membership process.
This prompted Turkey to veto all NATO cooperation with neutral Austria, although the crisis was partially resolved with a deal on Tuesday.