The Syrian president said Turkey and Jordan, who have provided refuge to Syrian refugees, are "playing with fire," Voice of America reported Saturday.
In comments to Turkish journalists, Assad accused Erdogan of conspiring with Israel to destroy Syria, contributing directly to the deaths of Syrians.
He accused Turkey and Jordan of allowing insurgents to train on their soil. The countries have allowed hundreds of thousands fleeing the conflict in Syria to live in camps just across the Syrian border.
Assad warned a "domino effect" would be produced if his government fell, Iran's Fars News Agency reported.
"The whole world knows that if Syria is partitioned, or if terrorist forces take control of the country, there will be direct contagion of the surrounding countries," he told two Turkish media outlets during interviews this week.
The consequences could be far-reaching, he said.
"This would mean instability for many years, even decades," Assad said.
Assad said any peace talks must be "intra-Syrian," conducted without any foreign involvement.
Syria claims the two years of rebellion have been orchestrated from abroad.