According to Reuters, President Erdogan announced on Monday May 16th that Turkey will not accept Sweden and Finland as new members of the North Atlantic Treaty Organization, NATO:
Erdogan said on Monday that Swedish and Finnish delegations should not bother coming to Ankara to convince it to approve their NATO bid. … Turkey surprised its NATO allies last week by saying it would not view [Swedish and Finnish] applications positively, mainly citing their history of hosting members of groups Ankara deems terrorists.
The Turkish government is primarily critical of how Sweden has allowed the Kurdish PKK to operate with virtual impunity. The PKK, which opposes Turkish control over Kurdish territory, is classified as a terrorist organization by the U.S. State Department and the European Union. According to the government in Ankara, Sweden has long acted as a sanctuary for the PKK, a fact that must change if Turkey is going to be favorable to the Swedish NATO application.
Turkey said on Sunday that Sweden and Finland must provide security guarantees on the Kurdistan Workers’ Party (PKK) and lift all arms embargoes against Ankara before it can support their Nato membership bids. [Foreign Minister] Cavusoglu said Ankara was making progress with Finland on the issue but Swedeen was continuing to be “provocative”, and that Turkey would only be happy after getting security assurances.
The Daily Sabah reports that the Turkish government has requested the extradition of a total of 21 individuals from Sweden, of which 11 are members of the PKK and 10 belong to the Gülenist Terror Group. A similar extradition request has been extended to Finland. Both countries have reportedly rejected the Turkish demands.