His assessment was based in part on meetings he held with both sides last month in Georgia and Abkhazia. The decision of each side to send a representative to UN-brokered talks in Geneva next month is another positive sign, he said.
After yesterday's closed briefing with the Security Council, Guehenno told RFE/RL why he thinks there might be new momentum.
"There is a willingness on the part of the two sides to look at the practical matters where they can make progress -- IDP [internally displaced persons] returns, economics, security guarantees," he said. "There is a certain willingness to engage, while at the same time, I think we have to be candid. The fundamental positions remain very far apart."
The UN peace process in Georgia has been limited to small-scale projects in the absence of major contacts between the two sides since last summer. Internal controversy over Abkhazia's self-styled presidential election caused a virtual suspension of the peace process until Sergei Bagapsh was declared the winner in January.
Guehenno said the Abkhaz leadership is not yet fully consolidated.
"I think Bagapsh really wants to get things done," Guehenno said. "He wants to show something to the people in Abkhazia. Obviously this is an arrangement which is still fragile. That's why I say 'cautious optimism.' I think there is some space that has opened, but one shouldn't expect any major breakthrough anytime soon. But there is a possibility again of some movement after a period when things were stalled."
The United Nations does not recognize the Abkhaz elections as legitimate, and the Security Council has repeatedly affirmed the need to respect the territorial integrity of Georgia. Security Council resolutions call for the two sides to resume political talks based on a scenario in which Abkhazia remains part of Georgia.
For his part, Bagapsh has reiterated the province's claims for independence.
But UN officials are hopeful that the new Abkhaz administration will resume stalled efforts on initiatives such as permitting the safe return of Georgian displaced persons to the Gali region, near the mutual border.
UN envoy Heidi Tagliavini told RFE/RL yesterday that the reappointment this week of Sergei Shamba as de facto foreign minister and the decision to send him to Geneva next month are encouraging.
"They are ready to work on economic issues, confidence-building measures, and really to engage in a dialogue," she said. "I think for the time being, this is excellent."
The meeting in Geneva is set for 7 and 8 April. In addition to Georgian and Abkhaz officials, Guehenno, Tagliavini, and high-level envoys from Russia, the United States, Britain, France, and Germany will attend.