Growing ties between Turkey and Iran are causing concern in some parts of the European Union and could provide ammunition for opponents of Ankara's drive to join the wealthy bloc. Although EU entry is Ankara's priority, the ruling AK party has increased Turkey's influence in the Middle East. In the past few weeks, Prime Minister Tayyip Erdogan has visited Tehran and Turkey has hosted Iran's president at a summit of Islamic countries. Some European countries say Turkey's improved ties with Iran could help EU policy in the Middle East and boost world powers' efforts to stop Iran developing a nuclear bomb. Others fear Ankara could be turning its back on Europe and its policy could hinder talks on Iran's nuclear enrichment program by reducing Tehran's isolation. “Policymakers in the West are getting worried that Turkey's growing ties with Iran – by lessening that country's sense of isolation – may frustrate diplomatic efforts to prevent Tehran from building a nuclear bomb,” wrote Katynka Barysch of the Centre for European Reform, a think tank in London. She also suggested some European countries could try to play up any differences in Turkish and EU policies to strengthen their arguments against Turkey entering the 27-country bloc. “This could play into the hands of those who say Turkey is not a European country,” she said by telephone. “No matter what Turkey does, it will always be interpreted one way by those who don't want Turkey in the EU and in another way by those who do.” Economic concerns Any shift of attention away from the EU by Turkey could undermine relations with one of Ankara's biggest trading partners and would be a concern for investors, who regard the EU accession drive as an anchor for financial and political reform. It would also worry the EU because, although some member states oppose Turkey joining the bloc, it is a potentially important energy transit partner offering an alternative to Russia as a source of supplies. French and British ministers have said Turkey's ties with the Middle East and Islamic countries could benefit the West. US President Barack Obama has said Turkey can play a positive role in easing the standoff with Tehran on nuclear issues. But German Chancellor Angela Merkel has privately expressed concern about what she sees as a warming of relations between Ankara and Tehran. “Countries that have been almost rude to Turkey in dumping decades of EU commitments (on Turkey's accession) then accuse Turkey of acting in bad faith over Iran. It's a little rich,” said Hugh Pope of the International Crisis Group think tank. He warned against “sacrificing the EU-Turkey relationship for often short-term domestic political considerations” of governments facing public hostility to letting into the EU such a large but poor state with a Muslim population. Could Iran-Turkey ties help the EU? Ankara says having good ties with Iran and seeking EU membership are not mutually exclusive. In line with EU policy, it opposes Iran having nuclear arms and has offered to mediate between global powers and Tehran over its nuclear program. Although accession talks with Ankara have slowed almost to a halt because of slow progress on reforms and a territorial dispute with Cyprus, the EU's annual report on the talks last month mentioned no problems over Iran. “Turkey supports the EU position on Iran's nuclear program,” the report said. A group of elder European statesmen said in September the EU could gain much from Turkey's ties with Iran because Ankara had a “level and frequency of access to the Iranian leadership that is greater than that of EU countries.”