KHARTOUM, Sudan - United Nations Secretary General Ban Ki-moon urged Sudanese on Monday to seize the "historic opportunity'' of a new peacekeeping force in Darfur to start a conclusive round of peace talks to end the conflict.

Sudan's foreign minister responded positively, saying "making peace is a priority.''

At the start of his first trip to Sudan since taking the reins of the UN in January, Ban said the international community had stood by for too long "as seemingly helpless witness to this tragedy.''

But things are changing following the UN Security Council's approval of the first joint African Union-UN force and stepped-up efforts to get all rebel groups and the government back to the peace table, Ban said.

"We must all seize this historic opportunity,'' the secretary general told the United Nations Association of Sudan soon after his arrival on a week-long trip that will also take him to Chad and Libya.

"Everyone agrees that there is no military solution. We need a ceasefire now,'' he said, drawing applause from some in the audience of several hundred that included Foreign Minister Lam Akol.

"Most of all, I want to see the foundations of a lasting peace laid down. My goal is to lock in the progress we have made so far, to build on it so that this terrible trauma may one day end,'' Ban said. "Yet there must be a peace to keep. Peacekeeping must be accompanied by a political solution.''

Picking up on this appeal in his closing remarks, Akol said "that's why we all agree that making peace is a priority. It is something that we welcome.''

He singled out UN envoy Jan Eliasson in the audience, and his African Union counterpart Salim Ahmed Salim, saying they have been busy trying to get the splintered Darfur rebel movements to peace talks as fast as the African Union-UN "hybrid'' force moves to deploy, "because the two of them must move together.''

Akol also touted "the tremendous change'' in the relationship between Sudan and the UN since late 2005, a time when pressure was mounting against Sudan over Darfur.

"We moved from what appeared to be confrontation to fruitful dialogue and sitting together, thinking together and working together towards achieving our common objectives in maintaining international peace and security,'' he said to applause.

The foreign minister said the resolution authorizing the hybrid force was "not ordinary'' because it talks about development and the necessity of dialogue between the government and opposition forces, and because it was "arrived at through discussion and dialogue.''

UN officials have cautioned, however, that there are many obstacles to overcome. But they welcomed Akol's strong support for both the hybrid force and new political talks, which the UN hopes will get underway in October.

The Darfur conflict has left more than 200,000 people dead and forced 2.5 million to flee their homes.