Washington and Moscow remain at odds over how to proceed with pending peace talks between embattled Syrian President Bashar Assad and anti-government forces fighting to overthrow the longtime leader.
The impasse calls into question whether Syrian peace talks can begin before the end of the year, the start date sought by the United Nations.
"We were hoping that we would be in a position to announce a date today, [but] unfortunately we are not," Brahimi told reporters shortly after Tuesday's meeting.
"But we are still striving to see if we can have the conference before the end of the year," he added, according to Reuters.
Representatives from Britain, France and China, as well as diplomats from Iraq, Jordan, Lebanon and Turkey, and the Arab League were also in attendance.
One of the main stumbling blocks toward peace talks is possible Iranian involvement in those negotiations.
Moscow has repeatedly called for Tehran to be included in the talks, arguing Iran's exclusion would eliminate a key regional player in the Mideast from having a say in the process.
That said, the Obama administration has repeatedly slammed the idea of Iranian participation.
“I don’t think anybody with a straight face could argue that Iran has had a positive impact on developments in Syria,” White House press secretary Jay Carney told reporters in July, when the idea of Iran's involvement was first raised by former U.N. special envoy Kofi Annan.
The group will meet again on Nov. 25 in another attempt to set a start date for the talks, Brahimi said.
The U.N. envoy also hopes to have a list of possible delegates for the talks from Syria's opposition forces by that date.
But Brahimi was highly doubtful the large group of disparate rebel factions fighting in Syria would be able to come together and select delegates.
"They are divided. It is no secret for anybody. They are facing all types of problems and they are not ready," he said.
Russian officials blamed the United States for not being able to leverage its support for the Syrian opposition into a transitional government ready to take over the country.
"It is not just the representation of the opposition that is required, but the participation of an opposition delegation of a broad range of opposition forces. And this is what the Americans are failing to achieve," Russian Deputy Foreign Minister Gennady Gatilov told local media outlets in Russia.
The proposed peace talks are a piece of a larger Syrian disarmament of its chemical weapons stockpiles, brokered by the U.S. and Russia earlier this year.
Late last month, international inspection teams announced they had completed its dismantlement of Assad's chemical weapons
“The Joint Mission is now satisfied that it has verified — and seen destroyed — all of Syria’s declared critical production and mixing/filling equipment,” The Hague’s Organization for the Prohibition of Chemical Weapons (OPCW) confirmed in a statement last Thursday.
Inspectors have inspected 21 of the 23 sites declared in Syria, and 39 of the 41 facilitates located at those sites, the statement continued.
They did not visit the two remaining sites, however, because of safety and security concerns.
U.S. forces were poised to begin military strikes against Assad in retaliation for his use of chemical weapons against rebel positions near Damascus.
While Congress debated whether to grant the White House authority to intervene in Syria, the Russian-proposed disarmament deal put those strikes on indefinite hold.