United Nations Secretary-General Ban Ki-moon is urging leaders to focus on climate change, support nations transitioning to democracy in the Arab world and to push for advances in the stalling Mideast peace process.

Mr. Ban pledged “unrelenting” efforts to move the peace process forward during his opening remarks at the annual General Assembly meeting Wednesday. The debate over the Palestinian bid for full U.N. membership has taken the main stage at the annual gathering of more than 100 world leaders.

U.S. President Barack Obama is also addressing the assembly Wednesday in a speech focusing on the Mideast peace efforts and the U.S. response to the “Arab Spring.”

The White House says Mr. Obama is speaking about the “unprecedented mandate” to intervene in Libya as an example of what international cooperation can achieve, and discuss the U.S. response to a year of “seismic” democratic change in the Arab world.

A preview of the speech released Tuesday said the president was to speak about a “new era of engagement” in which his administration “ended needless American isolation on a range of issues.”

More than 30 other world leaders, including French President Nicolas Sarkozy, will address the assembly on Wednesday in what is commonly referred to as the general debate portion of the annual meeting.

The Palestinian effort to secure statehood recognition by the U.N. Security Council has become the central focus of the week-long meeting. The United States and its key diplomatic partners are involved in intense diplomacy to block the Palestinian government's bid. President Mahmoud Abbas will submit the application for full U.N. membership to the Security Council on Friday.

White House Deputy National Security Adviser Ben Rhodes said Tuesday the president will underscore firm U.S. support for Israel, while also emphasizing that any meaningful solution must come about by direct negotiations.

Immediately following the speech, President Obama plans to meet with Israeli Prime Minister Benjamin Netanyahu. He will meet with Mr. Abbas later in the day.

On Tuesday, world leaders met to discuss international support for Libya's transitional government. U.N. Secretary-General Ban Ki-moon chaired the Libya Contact Group meeting, where he said the challenges Libya faces are “large.”

President Obama assured the Libyan leaders that they will have a “friend and partner” that will assist them in developing security, providing humanitarian aid and peacefully transitioning to democracy.