Zambian President Levy Mwanawasa has met opposition leader Michael Sata amid tensions over delays to the country's new draft constitution.
Mr Sata is against the idea of a national referendum
The meeting was the first between the two men since last September's bitter elections, which Mr Mwanawasa won.
His government has since been accused of delaying work on the new constitution, which calls for reducing the powers of the president.
Last month, he called for a national referendum on the constitution.
"We have no lingering doubts that Zambia needs a new constitution urgently," Mr Sata said in a statement, according to the Associated Press (AP). "We urge government not to procrastinate."
The meeting is the first of its kind since President Mwanawasa took power in 2001.
Civil and church groups have accused the government of trying to tamper with the new constitution.
"The referendum is totally unnecessary and, as a political party, we reject it and will not support it," Mr Sata was quoted by AP.