The US stressed Monday that the Palestinian Authority is responsible for stopping all acts of violence. State Department spokesman Sean McCormack told reporters that the US would like to see the situation in the Gaza Strip calming down. "We urge both sides to exercise restraint and avoid steps which further escalate the situation," McCormack said. The US is not negotiating with Hamas over the release of Gilad Shalit, the Israeli soldier captured Sunday near the Gaza border. Diplomatic sources said that Washington is now focusing its effort on pressuring Palestinian President Mahmud Abbas to take action and encouraging the Egyptians to continue their efforts to bring the crisis to an end.