BEIRUT, Lebanon — Representatives of Syria’s warring parties gathered in Geneva on Monday for the seventh round of peace talks, as a limited truce, negotiated by their big-power backers, appeared to be holding for a full day in southwest Syria, according to local residents and human rights monitors.

The cease-fire, negotiated by the United States, Russia and Jordan, applies to a strategic area across southwest Syria, near its border with Jordan and the Israeli-occupied Golan Heights.

The choice of southwest Syria for a truce reflected the relative stability of the front lines in the area and the small number of extremist fighters among the rebels who could act as spoilers, according to an official involved in the negotiations. The official spoke on the condition of anonymity because he was not authorized to brief the news media.

Southwest Syria also has been viewed with increased concern by both Israel and Jordan over what they describe as advances made by Iranian-backed militias fighting alongside the Syrian government, including Hezbollah. A successful cease-fire would stop such advances.