"We very much welcome President Mbeki's reconciliation initiative, which we understand is making good progress," said British Prime Minister Gordon Brown's spokesman, Michael Ellam. "We hope any agreement that is reached will be acted upon."
Ellam spoke at a summit of the Commonwealth, a 53-nation grouping composed largely of Britain and its former colonies. The group does not include Zimbabwe, which left the Commonwealth in 2003 after being suspended for widespread human rights abuses under President Robert Mugabe.
Officials added Brown was sticking with his plan to skip an African-European summit planned for next month in Portugal if Mugabe was present. Portugal invited Mugabe, and Mugabe has said he would attend.
Mbeki, who stopped in Zimbabwe on his way to Uganda this week, has been holding talks aimed at forging an agreement for elections between Mugabe's ruling Zanu-PF party and the opposition Movement for Democratic Change.
On Wednesday, Zimbabwean opposition leader Morgan Tsvangirai said the talks had made progress, but called on the Commonwealth to monitor their progress and ensure any commitments were honored.
"I am confident that the agenda set through the (South Africa-led) mediation will address the fundamental concerns around holding free and fair elections," Tsvangirai said.
"But we want to translate those ideas onto something on the ground so people can feel confident that the situation is safe; that there is a stop to violence."
Zimbabwe is not on the official agenda for the three-day meeting that began Friday, but officials said the leaders were likely to discuss the issue informally.