Abd Allah Masud said on Tuesday he would not negotiate unless his men holding the Chinese engineers were allowed to leave their besieged base with the captives.
"I will not hold any negotiations with the Jirga (tribal elders)
unless the Chinese are allowed to travel to my place without any threat," he said from an undisclosed location.
"I have not met anyone for the purpose of negotiation today," he said, denying an intelligence official's claims in north-western Peshawar that Masud had met with the tribal elders.
Masud's group seized the two Chinese men on Saturday as they drove to a hydro-electric dam project they were working on near Jandola, 75km from the Afghan border in the semi-autonomous South Waziristan region.
The elders reached Masud's hideout after midday on Tuesday only to be told that the leader would not speak to them until his demands were met by the government, a local official said.
The captors are surrounded
by security forces
The delegation was hoping to persuade Masud, who was freed from the US' Guantanamo Bay detention centre in March this year after spending 25 months there, to drop threats to kill the captives and release them.
Masud said he would not give any guarantees of the captives' safety if the government did not accept his safe passage demand.
He set two deadlines to execute one of them on Monday, demanding security forces end their siege of the hideout and let the captors go free, but allowed both to pass without harming the engineers.
The captors are surrounded by government security forces backed by members of the Jalakhel tribe. Pakistan's interior ministry said on Monday the engineers and their captors were both rigged with explosives.
"If you are a terrorist's spokesman, then you are a terrorist"
Information Minister Shaikh Rashid, speaking to the media
Information Minister Shaikh Rashid said the government could
consider "reasonable demands" of the abductors to secure the Chinese men's safe release.
But Rashid warned journalists not to "glorify" any statements
from the captors.
"We will take serious action if a militant's statement is carried to glorify him as a hero," he said.
"Today we just warn the media. We hope that they will take
notice of this warning," he added. "If you are a terrorist's
spokesman, then you are also a terrorist."
Tribal leaders say Masud has replaced former pro-Taliban
The Chinese men were seized in
the South Waziristan area
commander Nek Muhammad, who was killed in a missile strike by Pakistani forces in South Waziristan in June.
Chief negotiator Maulana Miraj al-Din said he had met Masud after Monday's last deadline passed and the captives were safe.
"I have told Abd Allah Masud not to take any rash decision.
Nobody knows if the crisis will end peacefully or there will be
violence," he said.
The abduction of the Chinese is a major source of embarrassment for Pakistan, which considers China one of its oldest and most trusted allies.
Beijing has urged Islamabad to "spare no effort" to rescue the
captives and to step up security for Chinese personnel working on Pakistani projects.