Senegal's National Assembly President Ousmane Sonko has slammed the government's decision to pursue a G20 debt restructuring framework, insisting the country's financial problems could have been resolved without it.

African Union Commission Chairperson Mahmoud Ali Youssouf urged renewed commitment to continental unity, integration and development while spotlighting water security as a priority for the continent's future.

The G20's newly adopted Declaration outlines four high-level priorities, which President Cyril Ramaphosa says position the bloc on "how we can organise ourselves to be more focused on our core mandate."

The declaration was unanimously adopted at the opening of the leaders' summit.