US President Joe Biden is expected to meet his Turkish counterpart Recep Tayyip Erdogan on the sidelines of the Nato summit on Wednesday, a day after discussions with the leaders of Sweden and Finland in Madrid.
Mr Erdogan has opposed the two Nordic countries joining Nato, claiming they have links to the PKK, a terrorist group proscribed by the US and other Nato states.
The meeting between the two leaders could play a crucial role in breaking down Ankara's resistance to bids by Sweden and Finland to join the Western military alliance following Russia's invasion of Ukraine.
US National Security Adviser Jake Sullivan told reporters on Tuesday that Mr Erdogan “will have the chance to meet with Mr Biden at some point on Wednesday.”
Before arriving in the Spanish capital, Mr Erdogan said talks were held with Mr Biden's team on Tuesday morning.
“He expressed his desire to get together tonight or tomorrow. We said it was possible,” Mr Erdogan said, before flying to Madrid.
Talks between the Turkish, Swedish and Finnish leaders and Nato Secretary General Jens Stoltenberg were continuing on Tuesday.
Turkey wanted to see the results of preparatory talks held on Monday in Brussels before deciding whether Sweden and Finland had done enough to lift its objections to their membership of the military alliance
Ankara, as a member of Nato, can veto both applications at the summit.
“We are a 70-year-old member of Nato. Turkey is not a country that randomly joined Nato,” Mr Erdogan said.
“We will see what point they [Finland and Sweden] have reached,” he said. “We do not want empty words. We want results.”
Washington, however, is confident that Finland and Sweden's candidacies will be approved.
“We also believe that Finland and Sweden have taken significant steps forward in terms of addressing Turkey’s concerns,” Mr Sullivan told reporters aboard Air Force One on its way to Madrid on Tuesday.
“We also believe and are confident that ultimately they will become members of the alliance and that Turkey’s concerns will be fully addressed.”
Mr Stoltenberg said the alliance had to “take into account” the security interests” of all members and would meet Turkey’s leader to discuss Sweden and Finland’s application to join the organisation.
“Turkey has expressed some serious concerns on issues like terrorism, and we all know that no Nato ally has suffered more terrorist attacks than Turkey,” Mr Stoltenberg said.
“Thousands of people have been killed by the PKK and other groups.”
He promised to discuss with Turkey how “we step up to do more together and fight terrorism” but part of the accession process was dialogue. “I have spoken several times with President Erdogan, with the Finnish president and the Swedish prime minister. I will meet with them later on today and I hope that we can make some progress.”
Sweden and Finland went into the summit open to the possibility that Turkey may only lift its objections after the summit concludes on Thursday.
“We have made progress. That is definitely the case,” said Swedish Foreign Minister Ann Linde.
“We are prepared for something positive to happen today, but also for it to take more time,” she added. “We must be patient and continue discussions even after the summit.”
Finnish President Sauli Niinisto said he was neither “optimistic nor pessimistic at this stage”.
