Erdogan laid down his country's position as German Chancellor Angela Merkel said that in order to progress in EU entry talks Turkey must open its ports to ships and planes from Cyprus and help press Iran to stop its controversial nuclear program.

Merkel said Turkey's membership talks are “open-ended,” but did not repeat her long-standing suggestion to give Turkey a “privileged partnership” that falls short of full EU membership. Germany is committed to existing agreements and “we are continuing the membership talks,” she stressed before reporters at a joint news conference with Erdogan.

She continued to put pressure on Turkey, urging the country to side with the United States and Europe to try to tamp down Iran's nuclear ambitions ahead of the upcoming Nuclear Security Summit scheduled in Washington in mid-April.

Turkey says neighboring Iran has the right to develop nuclear energy for peaceful use. Western nations are pushing for a new round of UN sanctions against Iran because they fear its nuclear program is geared toward making weapons.

“From Germany's point of view, we hope that Turkey will vote with the United States and Europe in the meeting in April,” Merkel said.

Erdogan responded by pointing to the nuclear arsenal of “another country,” a clear reference to Israel, which is widely believed to have a secret nuclear weapons program but which he said escapes sanctions.

“For us, Iran's situation is very different. We have a 380-kilometer (235-mile) border and centuries-long friendship and it is our second largest partner in energy after Russia - we can't ignore this,” Erdogan said.

“Imposing sanctions is not the right way, it would not be healthy in our region - the best way is diplomacy.” Turkey began EU membership talks in 2005, but negotiations on some policy have been frozen over Turkey's refusal to allow ships and planes from Cyprus to enter its ports and airspace, and the EU says Ankara must open its airpsace to the EU member if it wants to get closer to membership itself.

In return, Turkey insists on the lifting of what it says is the unofficial trade embargo on the breakaway Turkish Cypriot state in the north of the island, which was divided into a Greek Cypriot south and a Turkish Cypriot north following Turkey's 1974 invasion.

Merkel pointed out Monday that the “Cyprus question hasn't been cleared up” and said she planned to continue discussing the question of Cyprus with Turkey, saying a resolution “is in all our interests.” The EU has agreed to open part of accession talks with Ankara that deal with the environment, a move seen as rewarding recent reforms including moves to improve the rights of the country's Kurdish minority.

On a bilateral issue, Erdogan asked Merkel's support for the establishment of Turkish-language schools in Germany, reciprocating the existence of several German-speaking schools in Turkey. He said the Turkish parliament on Tuesday would pass a law to open a Turkish-German university as well.

The long-standing proposal has annoyed German authorities who have stressed the need for integrating millions of Turkish-origin immigrants into German society, but Merkel on Monday appeared to have softened her stance.

“If Germany has foreign schools in other countries, for example in Turkey ... then of course Turkey also can have schools in Germany,” Merkel said. “But what must not be the case is that that is an excuse for Turks living in Germany not to learn the German language.” Germany is home to 2.7 million people of Turkish origin; an estimated 500,000 are German citizens. While many are fully integrated, others speak German poorly and tend to stay within large Turkish-speaking communities.