Parties in the Mideast peace talks starting Thursday in Washington should not let negotiations be derailed by "cynical" attacks by militant groups, UN Secretary General Ban Ki- Moon said in Vienna, DPA reported.
The first direct talks between Israel and the Palestinian Authority in nearly two years have been overshadowed by bloody attacks launched by Palestinian Hamas militants against Israelis on Tuesday and Wednesday.
Ban also expressed hope that Israel and the Palestinians would enter the talks with a sense of pragmatism and flexibility.
"I know it will not be an easy process," he told reporters on a visit to the Austrian capital.
Although he was "very encouraged and happy" about the negotiations, Ban said it would take hard work to avoid political and security hurdles.
"We have already seen some such attempts by very cynical groups who really want to derail this peace process," he added. "That we have to guard against."
Four Israelis were killed and two were wounded in the attacks in the West Bank this week.
Ban was in Vienna for the opening of the International Anti- Corruption Academy, an institution set up by the United Nations and the European Union.