Turkish President Tayyip Erdogan said Western missions would "pay" for issuing security warnings and temporarily closing consulates in Turkey last week, while police said there was no serious threat to foreigners after detaining 15 Islamic State suspects on Sunday.
Ankara summoned the ambassadors of nine countries on Thursday to criticise their decisions to temporarily shut diplomatic missions and issue security alerts. Turkish officials said the following day that Western nations, including the United States and Germany, had not shared information to back up their claims of a security threat.
"The other day our foreign ministry summoned all of them and gave the necessary ultimatum, told them 'You will pay for this heavily if you keep this up,'" Erdogan said during a meeting with youth that was pre-recorded and broadcast on Sunday.
Alongside the closures, several Western states warned citizens of a heightened risk of attacks to diplomatic missions and non-Muslim places of worship in Turkey, following a series of far-right protests in Europe in recent weeks that included several incidents of burning copies of the Muslim holy book, the Koran.
Turkey suspended negotiations for Sweden and Finland's NATO accession last month following a protest in Stockholm during which a copy of the Koran was burned.
Erdogan said that the Western states were "playing for (more) time" and that the "necessary decisions" would be taken during Monday's cabinet meeting, without elaborating.
'NO CONCRETE THREATS'
Earlier on Sunday, police said they had not found evidence of any concrete threat to foreigners in the detentions of 15 Islamic State suspects accused of targeting consulates and non-Muslim houses of worship, state media reported.
Anadolu Agency cited an Istanbul police statement saying the suspects had "received instructions for acts targeting consulates of Sweden and the Netherlands, as well as Christian and Jewish places of worship".
While the suspects' ties to the jihadist group were confirmed, no concrete threats toward foreigners were found, the statement said.
Foreign Minister Mevlut Cavusoglu repeated on Saturday Turkey's frustration with what it says is Sweden's inaction toward entities that Ankara accuses of terrorist activity. All 30 NATO members must ratify newcomers.
Turkey, Sweden and Finland signed an agreement in June aimed at overcoming Ankara's objections to their NATO bids, with the Nordic states pledging to take a harder line primarily against local members of the banned Kurdistan Workers Party (PKK), which took up arms against the Turkish state in 1984.
(Editing by Jonathan Spicer, Elaine Hardcastle and Frances Kerry)