ISTANBUL Turkish President Tayyip Erdogan said Sweden has taken steps in the right direction for its NATO bid with anti-terrorism legislation but continued protests there by Kurdish militant sympathisers undermined its moves, Erdogan's office said.

The Turkish presidency said Erdogan made the comments in a telephone call with Dutch Prime Minister Mark Rutte, amid doubts that Ankara will lift its opposition to Sweden joining NATO in time for the bloc's summit in Lithuania on July 11-12.

Sweden and Finland applied to join NATO last year, ditching policies of military non-alignment after Russia's invasion of Ukraine. Applications must be approved by all NATO members, but Turkey and Hungary have yet to clear Sweden's bid.

Turkey has repeatedly said Sweden must take more steps against supporters of the outlawed Kurdistan Workers Party (PKK) and members of a network Ankara holds responsible for a 2016 coup attempt. Turkey designates both as terrorist organisations.

"President Erdogan said Sweden has taken steps in the right direction by making changes in anti-terrorism legislation," the statement said.

"But supporters of the PKK...terrorist organisation continue to freely organise demonstrations praising terrorism, which nullifies the steps taken," it quoted him as saying.

In recent months, demonstrators in Stockholm waved flags showing support for the PKK, which is also deemed a terrorist group by Turkey's Western allies, including Sweden.

Sweden says it has upheld its part of a deal struck with Turkey in Madrid last year aimed at addressing Ankara's security concerns, including a new anti-terrorism law.

(Reporting by Daren Butler; Editing by Alistair Bell)