Turkey and Syria have agreed to bury their differences, ending decades of frosty relations.
Both leaders are making regional stability a priority
Syrian President Bashar al-Assad, who is visiting Turkey, said the two countries would work together for peace and stability in the Middle East.
Mr Assad's visit is the first to Turkey by a Syrian head of state.
After a meeting with Turkish President Ahmet Necdet Sezer, he said the two countries shared concerns about the territorial integrity of Iraq.
Meanwhile Turkey, with its strong ties to Israel, is reported to be offering to help Syria make progress with its recent overtures towards the Jewish state.
Syria and Turkey were on the verge of war only five years ago over charges that Damascus was harbouring Kurdish rebels including Abdullah Ocalan. Syria later expelled the Kurdish rebel leader, who was subsequently captured and tried by Turkey.
But since succeeding his father Hafez al-Assad almost four years ago, Mr Assad has been trying to improve ties with Ankara, and his visit caps a series of smaller steps to repair relations.
"We have moved together from an atmosphere of distrust to one of trust," he said. "We must create stability from a regional atmosphere of instability."
Mr Sezer echoed the Syrian leader's concern: "No time can be lost in replacing the atmosphere of enmity, distrust and instability which unfortunately prevails in our region with one of peace, stability and prosperity."
Mr Assad also mentioned Iraq, whose US-led occupation - which the two countries oppose - has brought the two countries closer together.
"We condemn all approaches that pose a threat to Iraq's territorial integrity," he said.
Turkey and Syria have common interests in Iraq. Both have sizeable Kurdish populations and neither wants to see the Kurds of Iraq winning independence under the new constitution there.
The two countries also want foreign troops to leave Iraq as soon as possible.
The US accuses Syria of seeking weapons of mass destruction, and has threatened sanctions.
But Damascus will only renounce its weapons of mass destruction programmes in tandem with similar dismantling by Israel, Mr Assad said in an interview as he arrived in Turkey.
He said it was "natural" for his country to wish to defend itself without co-ordinated disarmament throughout the Middle East.
Israel is widely believed to hold a nuclear arsenal, but has never admitted it.