ROME (Reuters) - The Israelis and Palestinians are serious about pursuing peace, United States Secretary of State John Kerry said on Thursday.

Kerry is due to meet Palestinian President Mahmoud Abbas and Israeli Prime Minister Benjamin Netanyahu on May 21 or 22 to try to revive long-stalled Middle East peace talks.

The talks collapsed in late 2010 in a dispute over continued Israeli building of Jewish settlements on West Bank land that the Palestinians want for a state.

U.S. President Barack Obama has allowed Kerry to talk with both sides to gauge their readiness to resume negotiations and perhaps reach an agreement but it is unclear if he has decided whether to put the United States' full muscle behind a new push.

"President Obama has made it clear to all the parties he wants to know if people are serious. And I think there are ways to prove whether or not people are serious. That's what I'm seeking on his behalf over the course of these next days," Kerry said at a news conference in Rome with Italy's foreign minister.

"I believe that the parties are serious," he added.

The main issues that would have to be resolved in a peace agreement include the borders between Israel and a Palestinian state, the future of Jewish settlements on the West bank, the fate of Palestinian refugees and the status of Jerusalem.

(Reporting by Naomi O'Leary; Editing by Barry Moody)