An international conference to support reforms in the Palestinian Authority has opened in London with warnings that the road to peace between Israel and the Palestinians is filled with pitfalls.

British Prime Minister Tony Blair has opened the one-day London conference with a word of caution: despite a recent thaw in tensions between Israel and the Palestinians, much work remains to be done.

"The peace process, it never happens just because of expressions of good will. It never happens just because we want it to happen. There has to be a patient, hard slog," he said.

Palestinian President Mahmoud Abbas also spoke, saying the Palestinians are putting their house in order as they seek international support for final settlement negotiations with Israel.

About 30 governments and international institutions have representatives at the London conference to pledge assistance in building up the Palestinians' government, economy and security forces.