Western countries are increasing pressure on Turkey to admit Sweden to Nato, as Stockholm makes a final push to overcome Ankara’s opposition to its membership.

Ulf Kristersson, Sweden’s prime minister, writes in the Financial Times that a new anti-terror law entering force on Thursday delivers “on the last part” of an agreement to secure Ankara’s support for entry into the military alliance.

“It is time to seriously consider Sweden’s application for Nato membership . . . Only [Russian president] Vladimir Putin has anything to gain from Sweden remaining outside Nato,” Kristersson said.

A senior Swedish official said: “This terror law is our big hope for unlocking the situation. Then it’s up to Turkey to decide.”

Sweden’s request to join Nato last year following Russia’s invasion of Ukraine represents a historic shift from more than two centuries of military non-alignment.

But Turkey’s president Recep Tayyip Erdoğan has to date blocked Swedish membership, while allowing Finland to join Nato, arguing that Stockholm needed to do more to fight terrorism.

The impasse has driven a rift between Turkey and its Nato allies at a time when the alliance is trying to project unity over Russia’s war.

It has also called into question Nato’s open door policy of welcoming in new members.

While US and other Nato allies were tolerant of Erdoğan’s desire to bolster his agenda ahead of Turkey’s presidential election, which concluded at the weekend, they have now stepped up efforts to convince him to relent.

Nato secretary-general Jens Stoltenberg on Tuesday said it was “absolutely possible” to have Sweden in Nato by the alliance’s July 11 Vilnius summit. He tweeted he had a “good call” with Erdoğan on Tuesday in which the two discussed “finalising Sweden’s accession to Nato”.

“My message is that it’s within reach . . . There is a window now. We are working hard to have this as soon as possible,” Stoltenberg said in Oslo, ahead of a two-day meeting of Nato foreign ministers.

US secretary of state Antony Blinken visited Sweden on Tuesday ahead of flying to the Nato meeting. “The time to move forward is now, we’d like to see that happen before the Vilnius summit,” he said.

US President Joe Biden spoke to Erdoğan on Monday to congratulate him on his re-election. “He still wants to work on something on the F16s [fighter jets],” Biden said. “I told him we wanted a deal with Sweden, so let’s get that done.”

Turkey is hoping to clinch a pact with the US to purchase billions of dollars worth of F16 fighter jets but the deal is being held up by Congress. The Biden administration approved a $259mn F16 upgrade package in April, shortly after Ankara agreed to allow Finland to join Nato.

Soner Cagaptay, director of the Turkish research programme at the Washington Institute for Near East Policy, predicted further brinkmanship from Turkey’s president, whose tough line on Kurdish terrorism was a central feature of his re-election bid.

“Congress is saying Turkey should take the first step and greenlight Sweden, Erdoğan will say, no, I want the Congress to take the first step and greenlight the F-16s and then I’ll move forward,” he said.

Signalling Ankara’s continuing concerns, Erdoğan’s communications director Fahrettin Altun wrote on Twitter that Turkey’s government “sincerely hope[d] that the new anti-terror law . . . will be properly enforced”.

He urged Sweden to stop what he claimed were plans for a demonstration on Sunday by members of the Kurdistan Workers party or PKK, which the US, the EU and Turkey all classify as a terrorist organisation.

Both Erdoğan and Kristersson have been invited to attend a summit in Moldova on Thursday of the European Political Community, a new continent-wide forum championed by Emmanuel Macron, president of France.

Erdoğan has been upset by events in Stockholm including the burning of a Koran in front of the Turkish embassy, the unfurling of a PKK flag in the centre of the capital, and the projection of pro-PKK symbols and messages on to prominent buildings.

Nordic officials said there was frustration in Sweden that the US had not pushed back harder against Erdoğan before but hoped it would do so now before the Vilnius summit.

Other Nato countries have urged Erdoğan to back Sweden’s membership, arguing it is vital for security in the Nordic and Baltic regions in the wake of the Ukraine invasion.

“We expect that Turkey will now ratify Sweden’s application,” Norwegian prime minister Jonas Gahr Støre said this week.