"The idea is to have a formal review ... so at a given moment we can see if Turkey has changed and whether we can take back that decision or ... toughen it," the source said.
In an interview with Reuters in Brussels, Olli Rehn, the EU enlargement commissioner, appealed to Merkel and Chirac not to press for a new deadline for Turkey to open its ports to Cyprus.
He said strict deadlines did not produce results and the Cyprus question was best solved by the UN.
EU foreign ministers are due to decide next week how hard to sanction Ankara for its failure to meet a treaty obligation to open its harbours and airports to traffic from EU member Cyprus, whose Greek Cypriot government it does not recognise.
Areas of negotiations
Matti Vanhanen, the Finnish prime minister, who holds the EU's rotating presidency, said on Tuesday the recommendation to suspend some parts of the negotiations was the right step.
The European Commission last week recommended that negotiations on eight of 35 policy areas should be halted because of Turkey's refusal to allow Greek Cypriot ships and planes to use its ports and airports.
Recep Tayyip Erdogan, the Turkish prime minister, has criticised talks and warned the EU not to push his country away from membership negotiations.