The foreign ministers of Sweden and Finland plan to travel "soon" to Turkey for talks to address Ankara's objections to NATO membership for the two Nordic countries, news agency TT reported, citing the Swedish foreign office.

Swedish Foreign Minister Ann Linde and Finnish Foreign Minister Pekka Haavisto would meet their Turkish counterpart, Mevlüt Çavuşoğlu, in the capital, TT reported.

After having informal talks with Turkey on the sidelines of a NATO meeting in Berlin, Sweden has announced it will send a diplomatic delegation to Turkey to discuss the country joining the alliance as well as Turkey’s concerns about its support to the PKK terrorist organization.

Earlier, Linde confirmed that the delegation will visit Turkey and said it will be sent to Ankara very soon to evaluate the ruling Social Democratic Party's decision in favor of joining NATO.

"We will send a group of diplomats to hold discussions and have a dialogue with Turkey so we can see how this can be resolved and what this is really about," Defense Minister Peter Hultqvist told public service broadcaster SVT similarly.

The move comes after Turkey had voiced reservations about the membership of Sweden and Finland, saying that these two countries have been acting as safe havens for terrorist organizations, including the PKK and its Syrian wing, the YPG.

Sweden's ruling Social Democrats dropped their 73-year opposition to joining NATO on Sunday and are hoping for a quick accession, abandoning decades of military non-alignment following Russia's Feb. 24 invasion of Ukraine.

Sweden's Prime Minister Magdalena Andersson announced Monday that Sweden will join Finland in seeking NATO membership in the wake of Russia’s invasion of Ukraine. Finland on Sunday also confirmed it would apply to join the Atlantic military alliance.

However, Turkey surprised its NATO allies by saying it would not view applications by Finland and Sweden positively, with President Recep Tayyip Erdoğan saying "Scandinavian countries are guesthouses for terrorist organizations".

Turkey said it wanted the Nordic countries to halt support for terrorist groups present on their territory, and lift bans on sales of some weapons to Turkey.

Foreign Minister Mevlüt Çavuşoğlu said Sunday that talks with Swedish and Finnish counterparts in Berlin had been helpful. The two countries had made suggestions to respond to Ankara's concerns, which Turkey would consider, while he had provided them proof terrorists were present on their territory, he said.

He singled out Sweden in particular, saying the PKK had held meetings in Stockholm over the weekend.

Nevertheless, he said Turkey did not oppose the alliance's policy of being open to all European countries who wish to apply.

"Security guarantees are definitely needed. They need to end their support for terrorist organizations," Çavuşoğlu told reporters on Sunday in Berlin.

"We explained to member countries during the NATO meeting the support of Sweden and Finland to terrorist organizations. We have voiced openly, especially the weapons support of Sweden. The statements of the Swedish foreign minister so far have not been constructive but provocative," he added and also mentioned that during a meeting with the two countries, a working proposal came to address Turkey’s concerns.

Turkey has not shut the door to Sweden and Finland joining NATO but wants negotiations with the Nordic countries and a clampdown on what it sees as terrorist activities, especially in Stockholm, Presidential Spokesperson İbrahim Kalın also said Saturday.

"We are not closing the door. But we are basically raising this issue as a matter of national security for Turkey," Kalın told Reuters in an interview in Istanbul.

Any country seeking to join the North Atlantic Treaty Alliance needs the unanimous support of the members of the military alliance. The United States and other member states have been trying to clarify Ankara's position.

Sweden and its closest military partner, Finland, have until now remained outside NATO, which was founded in 1949 to counter the Soviet Union in the Cold War. The two countries are wary of antagonizing their large neighbor but their security concerns have increased since Russia invaded Ukraine on Feb. 24.

Kalın said the PKK, designated a terrorist organization by Turkey, the United States and the European Union, was fund-raising and recruiting in Europe and its presence is "strong and open and acknowledged" in Sweden in particular.

"What needs to be done is clear: they have to stop allowing PKK outlets, activities, organizations, individuals and other types of presence to...exist in those countries," Kalın said.

"NATO membership is always a process. We will see how things go. But this is the first point that we want to bring to the attention of all the allies as well as to Swedish authorities," he added. "Of course, we want to have a discussion, a negotiation with Swedish counterparts."

Turkey, the second-largest military in NATO, has officially supported enlargement since it joined the U.S.-led alliance 70 years ago.

For years it has criticized Sweden and other European countries for their handling of organizations deemed terrorists by Turkey.

Article 5 of NATO's founding treaty says an attack on any NATO country should be seen as an attack on all. While Sweden and Finland have long had close relations with NATO, they are not covered by its security guarantee.

Turkey has criticized Russia's invasion, helped arm Ukraine, which is not in NATO, and tried to facilitate talks between the sides but opposes sanctions on Moscow. It wants NATO "to address the concerns of all members, not just some," Kalın said.

Kalın said Russia's sharp criticism of Finland and Sweden over their plans was not a factor in Turkey's position.

NATO and the United States said they were confident Turkey would not hold up membership of Finland and Sweden.

"I'm confident that we will be able to address the concerns that Turkey has expressed in a way that doesn't delay the membership," NATO Secretary-General Jens Stoltenberg said.

U.S. Secretary of State Antony Blinken declined to go into details of closed-door conversations in Berlin but echoed Stoltenberg's position.

"I'm very confident that we will reach consensus on that," Blinken told reporters, adding that NATO was "a place for dialogue."

Moscow's invasion of Ukraine on Feb. 24 has swung political and public opinion in Finland and neighboring Sweden in favor of NATO membership as a deterrent against Russian aggression.

Sweden and Finland were both neutral throughout the Cold War, and their decision to join NATO would be one of the biggest changes to Europe's security architecture for decades, reflecting a sweeping shift in public opinion in the Nordic region since Russia invaded its neighbor Ukraine in February.

Moscow has responded to the prospect of the Nordic states joining NATO by threatening retaliation, including unspecified "military-technical measures".

Russia's deputy foreign minister said on Monday that Finland and Sweden will not strengthen their security by joining NATO.

On the contrary, the general level of tension in Europe will increase, Sergey Ryabkov told reporters in Moscow.

"They should have no illusions that we will just put up with this ... in Brussels, in Washington, and in other NATO capitals ... the overall level of military tension will increase, and there will be less predictability in this area," Ryabkov said.

Asked about any possible steps Russia may take in response, the diplomat said moves will depend on "a practical outcome" of Finland and Sweden's admission to the military alliance.

"We will strengthen our borders and strengthen the Russian grouping of troops on the border" if NATO weapons are deployed close to Russia in Finland, Viktor Bondarev, head of Russia's upper house of parliament's defense and security committee, also wrote in a post on the Telegram messaging app on Sunday.

Finland's Niinisto, who spoke to Russian President Vladimir Putin on Saturday, said their conversation was measured and did not contain any threats.

"He confirmed that he thinks it's a mistake. We are not threatening you. Altogether, the discussion was very, could I say, calm and cool," Niinisto said in an interview with CNN's "State of the Union" program.