The Obama administration is trying to convince the US Congress to approve the sale of spy drones to Turkey for its campaign against Kurdish rebels, the Turkish president was quoted as saying Tuesday.

"Actually the administration has a positive stance (over the sale)," President Abdullah Gul was quoted as telling the Anatolia news agency in Chicago where he was attending a NATO summit.

"They (the administration) are trying to convince the Congress," he added.

The United States has deployed Predator drones to Turkey from neighbouring Iraq for surveillance flights in support of Ankara's fight against Kurdish rebels, Pentagon announced in November.

After US forces withdrew from Iraq in December, the four American unmanned aircraft were shifted from an air field in northern Iraq to the Incirlik air base in Turkey.

But Turkey wants to buy armed drones whose sale depends on an approval from Congress amid concerns that pro-Israeli lobbies may hinder such a sale due to Ankara's tense relations with the Jewish state.

A botched air raid launched by the Turkish military that killed 34 civilians in December may also complicate further sales.

Gul met with US President Barack Obama on the sidelines of the NATO summit late Monday.

"I've repeated our demands," said Gul. "It is necessary to trust, not envy such a country, which is an important ally. As you know, President Obama, Secretary of State Clinton and her assistants are doing their best."

Gul declined to say how many drones Turkey wants to buy from the United States.

The Kurdistan Workers' Party (PKK), listed as a terrorist organisation by Turkey and much of the international community, took up arms for Kurdish independence in southeastern Turkey in 1984.

It sparked a conflict that has claimed about 45,000 lives.