WASHINGTON, Feb 23 (Matt Spetalnick/Reuters) - President Barack Obama is expected to nominate Dan Shapiro, a top adviser who has helped craft the US response to popular unrest sweeping the Middle East, to be Washington's ambassador to Israel, a source familiar with the matter said on Wednesday.

Shapiro, an aide to Obama since the 2008 presidential campaign, is the senior director for the Middle East and North Africa on the White House National Security Council and has worked closely with U.S. Middle East envoy George Mitchell.

He has accompanied Mitchell on trips to Israel and the Palestinian territories on missions aimed at reviving peace moves, which Obama set as a high priority soon after taking office.

Those efforts brought the sides back to direct peace talks briefly but negotiations broke down late last year over Jewish settlement construction on occupied land.

With the Arab world caught up in a wave of uprisings that have toppled autocratic rulers in Egypt and Tunisia and brought turmoil to Libya and other countries, hopes remain low for getting the Israeli-Palestinian peace process back on track.

But Shapiro, as a trusted Obama foreign policy aide, would be positioned as ambassador to help push any new diplomatic initiative if Washington decides to launch one.

Shapiro helped Obama's presidential campaign as well as his administration with outreach to the American Jewish community, where he has had to work at times to overcome skepticism over Obama's commitment to Israel.

Shapiro previously worked in former President Bill Clinton's National Security Council and was also a staff member for the US House of Representatives Foreign Affairs Committee in the 1990s.

The White House sees Shapiro's nomination winning support from Democrats and Republicans alike, one source familiar with the matter said, speaking on condition of anonymity because the nomination has yet to be announced. The exact timing of an announcement was not immediately known.

If Shapiro's nomination is confirmed, he would replace current ambassador James Cunningham, who was named to the post in 2008 by former President George W. Bush.