The United Nations' new Middle East envoy says he and the U.N. secretary-general will engage Israel's new government to explore "realistic options" for a return to talks with the Palestinians aimed at a two-state solution within a reasonable time frame.

Nikolay Mladenov also used his first briefing to the U.N. Security Council on Tuesday to remind Israel that settlement activity is illegal under international law and to call on Israel's government to stop such actions.

The international community is looking for ways to revive talks after Israeli Prime Minister Benjamin Netanyahu said shortly before his re-election in March that he would not allow the establishment of a Palestinian state on his watch.

A French-proposed council resolution setting a framework for negotiations has been on hold as Israel's new government formed.