"The legitimacy of any elections hinges on a widely accepted result based on credible technical conduct of polling and inclusive participation," Kubis said in a statement from Kabul. "I would go so far as to say that women's participation will be a key measure of success in Afghanistan's upcoming polls."
Afghanistan holds presidential and provincial council elections in April.
The Independent Election Committee in Afghanistan said Wednesday it held coordination meetings with national and international observers. It says there are no women among the 11 candidates cleared to take part in the presidential contest, though 308 of the 2,713 candidates running for provincial council seats are women.
Kubis said, however, he was disappointed by a decision last year that reduced the quota for women serving on provincial councils.
"This was a wake-up call to us all of the need to protect and promote the gains of recent years," he said.
This year's election will mark the first time in Afghan history power will be handed peacefully from one democratically-elected government to the next.
Afghan President Hamid Karzai is ineligible to compete because of term limits.