"We are still going to talk. We are finishing tomorrow [Wednesday]," he said on Tuesday, adding that "one or two areas" were still outstanding.
Morgan Tsvangirai, leader of the MDC, said "there is a positive development" in the negotiations this time.
"Nothing has been concluded yet but we are hoping that tomorrow [Wednesday] we will be able to look at the outstanding issues."
Arthur Mutambara, leader of the breakaway MDC faction, was even more optimistic, saying "tremendous progress" had been achieved.
"We hope tomorrow we will be able to bring finality and closure to the dialogue process."
Thabo Mbeki, the South African president, is mediating in the talks in an attempt to secure a power-sharing deal to end the wrangling and help ease a post-election crisis.
Tsvangirai beat Mugabe in a March 29 presidential election but fell short of enough votes to avoid a June run-off, which was won by Mugabe unopposed after Tsvangirai boycotted it, citing violence and intimidation of his supporters.