Turkey has built close economic ties with Iran and has been at odds with Washington over the best way to get Tehran to halt its nuclear program, arguing for a diplomatic solution to the standoff instead of sanctions. However, Turkey has also decided to host a NATO defense shield radar that would warn of any Iranian ballistic missiles in the region.
The last round of nuclear negotiations was held in Istanbul in January 2011, but ended without agreement.
Iran's Foreign Minister Ali Akbar Salehi said he favored Istanbul as the venue for the April talks, but that a final decision is yet to be made by top Iranian nuclear negotiator Saeed Jalili and EU's foreign policy chief Catherine Ashton "within the coming days."
"Istanbul has expressed its readiness to host these talks and it remains one of the probable options for the negotiations," Salehi told the official IRNA news agency on Wednesday.
The U.S. and some of its allies accuse Iran of using its nuclear program as a cover to develop atomic weapons. Iran has denied the charges, saying the program is peaceful and aimed at producing electricity and radioisotopes to treat cancer patients.
The U.N. has imposed four rounds of sanctions against Tehran for its refusal to halt uranium enrichment, a technology that can be used to produce nuclear fuel or materials for bomb.
Also, the European Union as well as the U.S. and others have imposed an oil embargo as part of sanctions to pressure Tehran into resuming talks on the country's nuclear program. They have also imposed tough banking sanctions aimed at limiting Iran's ability to sell oil, which accounts for 80 percent of its foreign revenue.
Apart from Iran's nuclear issue, Erdogan and Iranian officials will also likely discuss the crisis in Syria -- an issue Tehran and Ankara vastly differ on.
Turkey has demanded that Assad step down over the yearlong conflict, which the U.N. says has left more than 9,000 people dead. Iran is a key ally of the Syrian regime and Ahmadinejad praised President Bashar Assad on Tuesday for the way the "Syrian authorities are managing the situation with confidence."
Turkey is to host about 60 countries, including the United States, for the "Friends of the Syrian People" conference in Istanbul on Sunday. The meeting will discuss ways to further isolate and pressure Assad, as well as measures to support the Syrian opposition.