Asked during a television interview if the United States had a probable date for the talks, Armitage said, "Yes we do, probably, starting around the 27th of this month in Beijing."
A Russian diplomat in Beijing earlier told AFP the talks would be held from August 27 to 29 at the vice ministerial level.
In a turnaround earlier this month North Korea agreed to the US proposal for the six-way talks on the crisis sparked by Pyongyang's decision to pursue a secret nuclear weapons program.
China, Japan, Russia and South Korea are also due to attend the talks.
Armitage declined to be brought out on whether he was confident the talks would succeed.
"It's not a matter of confidence or lack of confidence," he told the Australian Broadcasting Corporation. "We're having the talks, we'll do our best, we'll be businesslike, we'll be serious and sincere.
"Beyond that I'm not going to make any speculation -- it would be foolhardy."
Armitage, who has been meeting with Australian leaders in Canberra, also said the United States had accepted an Australian offer to provide experts and help in any verification program concerning North Korea's weapons programs.
"Any verification regime would have to be quite intrusive obviously, because there's a lack of faith and North Korean willingness to abide by their agreements," he said.
"I've had discussions with our Australian friends even during this trip about taking advantage of their experience in verification.
"They have made an offer and I have accepted it."
Armitage also said the top US envoy on North Korea, John Bolton, who recently infuriated North Korea by calling its leader Kim Jong-Il a "tyrannical dictator", would not take part in the six-nation talks.
"The US government will make the decision on who will participate in the upcoming six-way talks and Mr. Bolton was not scheduled and will not be participating in these talks," he said.