Ibrahim Kalin, Turkish President Tayyip Erdogan's spokesman and chief foreign policy adviser, meets with Swedish delegation, amid Russia's invasion of Ukraine, in Ankara, Turkey May 25, 2022. Presidential Press Office/Handout via REUTERS
Ibrahim Kalin, Turkish President Tayyip Erdogan's spokesman and chief foreign policy adviser, meets with Swedish delegation, amid Russia's invasion of Ukraine, in Ankara, Turkey May 25, 2022. Presidential Press Office/Handout via REUTERS Reuters / PRESIDENTIAL PRESS OFFICE

Talks between Turkish officials and delegations from Sweden and Finland this week in Turkey made little headway overcoming Ankara's objections to the Nordic countries joining NATO, and it is not yet clear when further discussions will take place, according to two sources.

"It is not an easy process," a senior Turkish official told Reuters on Friday. "They need to take concrete steps that will be difficult. Further negotiations will continue. But a date doesn't seem very close."

Finland and Sweden formally applied to join NATO last week to boost their security in the face of Russia's invasion of Ukraine.

All 30 NATO members must approve enlargement plans. But Turkey challenged the move saying the Nordic countries harbour people linked to what it calls terrorist groups, and because they have halted arms exports to Ankara. Turkish Foreign Minister Mevlut Cavusoglu said on Friday that his country expects Sweden and Finland to take concrete action and halt such support before it lifts its objections.

A separate person close to the situation said the Wednesday talks made no clear progress and ended with no timeline to continue, raising the prospect that Turkey may still oppose the membership bids when NATO holds a summit on June 29-30 in Madrid.

The Swedish and Finnish foreign ministries did not immediately reply to requests for comment on Friday.

The five-hour discussions were cordial and included separate sessions between Turkish officials and counterparts from the two Nordic countries, followed by three-way talks with all parties, the second source added.

A third source told Reuters that Turkish officials downplayed prospects of reaching an agreement before the Madrid summit.