Finnish President Sauli Niinisto and Swedish Foreign Minister Ann Linde said on Tuesday there had been some progress in negotiations aimed at overcoming Turkey's objection to the Nordic countries' bid to join NATO.
Turkey has blocked bids by Sweden and Finland to join the Western military alliance, accusing them of supporting groups Ankara views as terrorists.
NATO leaders are expected to urge Turkish President Tayyip Erdogan to lift his veto over their bids when they meet for a three-day summit in Madrid on Tuesday, as the West strives to send Russia and China a signal of resolve.
"We are prepared for the eventuality that something positive could happen today, but it might also take longer," Linde told daily Svenska Dagbladet (SvD).
Finland's Niinisto was slightly more cautious, saying there had been more mutual understanding in the talks but that he was neither optimistic nor pessimistic when it comes to the outcome ahead of his meeting with Erdogan, NATO leader Jens Stoltenberg and Swedish Premier Magdalena Andersson later today in Madrid.
"The general view is that the discussions went somewhat better, which should mean that understanding has somewhat increased on both sides," Niinisto told reporters, referring to preceding talks between diplomats.
Speaking before departing for the NATO summit in Madrid, Erdogan said the Nordic states must take Turkey's concerns into consideration and deliver not just words but results if they wanted to be NATO members.