Southern African leaders have been holding an emergency summit to discuss the political deadlock in Zimbabwe over last month's presidential elections.
However, Zimbabwe's President Robert Mugabe is not at the summit - he said he had other business to attend to.
Zambia's president, hosting the forum, said a blind eye could not be turned to Zimbabwe, but that Mr Mugabe was not "in the dock".
South African President Thabo Mbeki said there was "no crisis" in Zimbabwe.
He flew to Harare before the summit opened in the Zambian capital, Lusaka, to meet Mr Mugabe.
Mr Mugabe's Zanu-PF party lost its House of Assembly majority for the first time since 1980 in the 29 March poll, but no results have yet been released from the presidential race.
Opposition leader Morgan Tsvangirai says he won the vote, and hopes leaders will pressure Mr Mugabe to step down.
Call for patience
Opening the 14-nation Southern African Development Community (SADC) summit in Lusaka, Zambian President Levy Mwanawasa said it could not "stand by and do nothing when one of its members is experiencing political and economic pain".
"It would be wrong to turn a blind eye," he said, but added that the summit was "not intended to put President Mugabe in the dock".
SOUTHERN AFRICAN DEVELOPMENT COMMUNITY
Member countries: Angola, Botswana, DR Congo, Lesotho, Madagascar, Malawi, Mauritius, Mozambique, Namibia, South Africa, Swaziland, Tanzania, Zambia and Zimbabwe
Aims: Development, economic growth, regional integration, common political values and systems, promote peace and security
Role in Zimbabwe: Appointed South African President Thabo Mbeki to mediate in 2007 - new election law agreed but MDC later said talks had failed; sent election monitors for recent polls
Mr Mwanawasa called on Zanu-PF and the main opposition Movement for Democratic Change (MDC) to "seize the opportunity to turn over a new leaf".
He said there was "concern" in the SADC that the Zimbabwe Electoral Commission had not announced presidential poll results, which had "given rise to a climate of tension" and "left the international community in the dark".
Correspondents say the summit can achieve little without Mr Mugabe there, which is why Mr Mbeki stopped in Harare first.
Mr Mbeki called for patience over the unreleased results.
"If nobody wins a clear majority the law provides for a second run. If that happens I would not describe it as a crisis. It's a normal electoral process," he said.
Mr Mbeki has led mediation efforts between the two Zimbabwean sides since last year, but his "quiet diplomacy" approach has been criticised by some as ineffective.
The BBC's Peter Greste, in Johannesburg, says that rather than risk a public rebuke from his colleagues in Zambia, President Mugabe sent a delegation of government ministers.
The state-run Herald newspaper quoted Foreign Affairs Secretary Joey Bimha as calling the summit "unnecessary" because the votes were still being counted.
Justice Minister Patrick Chinamasa, part of Zimbabwe's delegation to the summit, told AFP news agency that his country would not accept Mr Tsvangirai's participation in the meeting.
Ahead of the summit, the MDC urged the African leaders to "speak strongly and decisively against the dictatorship".
MDC Secretary-General Tendai Biti said Zimbabwe was "at a crossroads" and the summit was a "critical meeting" for his country and the region.
'On the brink'
The summit comes amid growing international pressure on Mr Mugabe to release the results of the presidential poll.
UK Prime Minister Gordon Brown said he "cannot understand why it is taking so long to announce the result of the presidential elections"
Zimbabwe's police warned political parties against "creating mayhem"
Former UN Secretary General Kofi Annan warned that Zimbabwe was standing "on the brink".
Inflation is running at more than 100,000%, unemployment is around 80% and an estimated one-quarter of the country's population has left the country.
Zimbabwean police have banned political rallies "with immediate effect", amid growing tension over the disputed election.
The MDC has called for a strike starting on Tuesday to pressure the authorities, one day after a court is to rule on the party's bid to force the election commission to release the presidential poll results.
Mr Tsvangirai says he won the vote outright and has refused to take part in any run-off with Mr Mugabe.
He accuses Mr Mugabe of mobilising Zimbabwean security forces and pro-Zanu-PF forces to intimidate MDC voters.
The 84-year-old Mr Mugabe has ruled Zimbabwe since independence from Britain in 1980.