Turkey's President Recep Tayyip Erdogan put Sweden's Nato membership bid on hold as he demanded Stockholm show that it was committed to fulfilling its commitments on security.
Mr Erdogan outlined his demands as he emerged from an official meeting with Swedish Prime Minister Ulf Kristersson in Istanbul on Tuesday.
He also said recent resumption of arms exports to Turkey was a positive step, but said more must be done to combat the threat from Kurdish terror groups operating in the Nordic country.
Finland and Sweden are hoping that Mr Erdogan will clear their path to joining the alliance following Russia's invasion of Ukraine earlier this year.
"I want to reassure all Turks, Sweden will live up to all the obligations made Turkey in countering the terrorist threat," Mr Kristersson said.
Before leaving for Ankara, Mr Kristersson announced 10 million Swedish crowns ($923,000) of support for a Nato counter-terrorism fund.
He said Sweden would do “significantly more” to fight extremists at home, with new legislation to strengthen the hand of counter-terrorism authorities.
These are the latest steps taken by Sweden to assuage accusations from Turkish President Recep Tayyip Erdogan that it is soft on terrorism.
“The fact that the Swedish government takes terrorism and violent extremism very seriously is of course an important message to President Erdogan and to the Turkish government,” Mr Kristersson said.
“Ahead of our meeting in Ankara, I would like to tell you today that Sweden is further strengthening our international co-operation against terrorism.”
Nato's voluntary counter-terrorism fund supports projects such as preparing soldiers for improvised explosives and training weapons intelligence experts.
Turkish Foreign Minister Mevlut Cavusoglu described the meeting on Tuesday as critical.
Although Sweden and Finland have taken “some steps” to secure Turkey’s approval, it is “difficult to say they’ve fulfilled their pledges at this stage,” he said.
The three countries signed a pact in June in which Sweden and Finland agreed to take measures against Kurdish groups that Turkey considers terrorists.
However, Turkey has said it will not be content until it sees their promises turned into reality.
Mr Erdogan's office said the leaders would discuss Nato as well as Ankara's relations with the European Union, which recently said Turkey was no closer to joining the bloc.
Mr Kristersson, who replaced Magdalena Andersson as Sweden's prime minister last month, has promised to implement the deal without making further concessions to Turkey.
Since taking office, Mr Kristersson's government has ditched Sweden's flagship “feminist foreign policy” and opened the door to stationing Nato's nuclear weapons on its territory.
Both he and Finland's Prime Minister Sanna Marin have rejected the notion, hinted at by Mr Erdogan, that Finland could be allowed into Nato before Sweden.
Nato Secretary General Jens Stoltenberg also visited Ankara last week to urge Turkey to lift its veto.
The two Nordic countries turned a page on decades of neutrality to seek Nato membership after Russia's invasion of Ukraine redrew the security picture in Europe's far north.
Hungary, the only other Nato member yet to ratify Sweden and Finland's applications, has said its parliament will consider the matter next month.