U.N. Secretary-General Ban Ki-moon is calling for a peaceful solution to territorial disputes in the South China Sea, where China's assertiveness has alarmed its smaller neighbors.

Ban told reporters in Hanoi on Friday that he Vietnamese President Truong Tan Sang discussed regional security concerns, including the South China Sea. He said he had consistently called on all parties to resolve their disputes through dialogue and in conformity with international law.

Vietnam, along with the Philippines, is one of the most vocal critics of China's activities in the disputed waters, where Beijing has begun creating artificial islands through massive land reclamation. Other claimants include Malaysia, Brunei and Taiwan.

Ban says it is important to avoid actions that could provoke or exacerbate tensions in the region.