Diplomats from the three countries held their first trilateral talks in Helsinki under a Permanent Joint Mechanism established at the Nato summit in June.
That agreement cleared the way for Sweden and Finland to be formally invited to join Nato, after Turkey received assurances they would take a harder line on Kurdish groups it regards as terrorists.
But Turkey has yet to ratify their applications and has signalled it wants to see Sweden and Finland take concrete steps before it will sign them off.
At the meeting, Sweden and Finland "renewed their commitment to demonstrate full solidarity and co-operation with Turkey in the fight against all forms and manifestations of terror", Turkish government spokesman Ibrahim Kalin was quoted as saying by AFP.
Such is the desire to keep Ankara onside that Finland kept the meeting's location and timing under wraps until after it was over, citing security concerns for the Turkish delegation.
The Finnish government said delegates from its foreign, interior, justice and defence ministries and the intelligence services took part in the talks and agreed to continue them "during the autumn".
The participants "discussed the concrete steps to implement the trilateral memorandum" signed in Madrid, the Finnish statement said.
But there was no promise from Ankara to proceed with ratification, which is needed from all 30 Nato members and has been completed by 23 so far.
Sweden and Finland turned a page on decades of military neutrality to seek Nato membership after the Russian invasion of Ukraine sent a shiver of fear across the Baltic.
Turkey held up their applications, complaining that Kurdish terrorists were operating from Scandinavia and that dozens of extradition requests had resulted in nothing.
The agreement signed in Madrid called for extraditions to take place "expeditiously and thoroughly", and Sweden arranged its first such deportation this month.
But Turkey signalled it was not yet satisfied and President Recep Tayyip Erdogan said last month his country could still "freeze the process" if its demands are not met.
Ratifications are also pending from the Czech Republic, Greece, Hungary, Portugal, Slovakia and Spain, but none have signalled any objection.
Sweden and Finland can accede to the North Atlantic Treaty once all 30 members have deposited the relevant protocols with the American government.