Turkey's Prime Minister oversaw the signing of two nuclear agreements with China Monday on a trip to the Asian nation that also saw him make an unprecedented stop in ethnically-tense Xinjiang.

Recep Tayyip Erdogan -- on the first official trip to China by a Turkish premier in 27 years -- on Monday also held talks on Syria and Iran in Beijing with Chinese Premier Wen Jiabao after his stopover in the northwestern region.

The two agreements -- announced at a ceremony attended by Wen and Erdogan following their meeting -- pave the way for deeper nuclear cooperation between the two countries, but few concrete details were made available.

One of the accords signed is a letter of intent between China's National Energy Administration and the Turkish energy ministry for further nuclear cooperation, but no other information was given.

At the start of their meeting, Wen said Erdogan was the first Turkish prime minister to have visited Xinjiang -- home to around nine million mainly Muslim Uighurs who share linguistic and religious links with Turkey.

Ankara has in the past heavily criticised Beijing's actions in Xinjiang -- whose Uighurs have long complained of repression under Chinese rule -- but the two nations have nevertheless forged closer ties in recent years.

Wen said Erdogan had left a "good impression" but gave no further details about the stopover in Xinjiang's capital Urumqi on Sunday, which analysts say is significant given Ankara's past criticism.

Erdogan was the most vocal foreign leader to criticise China following deadly riots in July 2009 in Urumqi that killed at least 184 people.

At the time, he urged China to stop the "assimilation" of the Uighur minority, and blamed Beijing for failing to stop the ethnic violence, which he compared to a "genocide."

The Xinjiang stopover "is quite unexpected as... it's very difficult for Turkish diplomats to go to Xinjiang, they don't easily get the authorisation as they speak a similar language (to Uighurs)," said Jean-Pierre Cabestan, politics professor at Hong Kong Baptist University.

"It shows that in the Sino-Turkish relationship, Turkey is not in a weak position, and is even in a strong position," he said, adding China needs Turkey's support in the Middle East.

During their closed-door talks, Wen and Erdogan touched on the crisis in Syria as well as global tensions over Iran's disputed nuclear activities, China's state television reported, without giving further details.

The army in Syria is due to withdraw from protest cities Tuesday under a peace deal brokered by former UN chief Kofi Annan, with a complete end to fighting set for 48 hours later.

But the Damascus regime has since said it will only carry out its side of the bargain if rebels first hand over written guarantees to stop fighting -- a demand rejected by rebel army chief Colonel Riyadh al-Asaad.

Turkey and China hold different positions on the conflict in Syria, where pro-democracy protests have been brutally repressed for more than a year.

Erdogan, once an ally of Syrian President Bashar al-Assad, has threatened to take action should Damascus fail to comply with the Annan plan. China rejects any foreign interference in the country's internal affairs.

Iran, meanwhile, confirmed Monday that nuclear talks with world powers would take place in Istanbul as planned on Saturday despite a sharply-worded row with Turkey.

Last week, Iranian officials said Turkey's support of the opposition in Syria -- Iran's chief ally -- excluded Istanbul as a venue. They proposed Baghdad or Beijing instead, but Monday came round to using the Turkish city.

The two countries -- whose mutual trade has soared from just $1 billion in 2000 to $19.5 billion in 2010 -- on Monday also signed agreements in the fields of media, publishing, investment and culture.