Tripoli, Libya (CNN) -- Libyan officials are rejecting rebel claims that Moammar Gadhafi is seeking refuge for his family, saying Friday that neither the leader nor his wife and children plan to leave the country.
Libyan Deputy Foreign Minister Khaled Kaim told CNN that Gadhafi and his family are staying in the country, countering rebel reports that the governments of Egypt, Morocco, Tunisia and Algeria have been asked to accept the family.
U.S. and NATO officials also say they have no indication Gadhafi is making preparations to leave.
Abdel Monem al-Houni, a representative of the rebel Transitional Council in Cairo, told CNN he was informed about the request by the Arab governments who received it.
Kaim said the four governments could speak on their own behalf about the rebel claims.
The reports come as U.S. officials say the embattled leader may be making preparations for a last stand in Tripoli as a months-long NATO air campaign continues amid reports of rebel advances.
"We believe he could be planning for a last stand," one U.S. official said.
A second U.S. official confirmed a similar concern and said the Gadhafi plan could involve a final military offensive against civilians, launched from his last major strongholds around the Libyan capital.
The officials, who have knowledge of the situation on the ground, did not want to be named because of the sensitive intelligence matters.
In an address broadcast on Libyan state television Monday, Gadhafi urged supporters to take up arms and battle rebel forces.
"Move always forward to the challenge; pick up your weapons; go to the fight in order to liberate Libya inch by inch from the traitors and from NATO. Be prepared to fight if they hit the ground," Gadhafi said.
Both U.S. officials emphasized that if a final push by Gadhafi happens, the United States doesn't have a clear idea what form it could take.
However, State Department spokesman Mark Toner said Friday that U.S. officials in Benghazi have been working with the Libyan opposition "on exactly what it's going to look like post-Gadhafi."
"Impossible to say when he'll go, but it's clear that he will go," Toner told CNN's Brooke Baldwin.
Meanwhile Friday, opposition forces said a former Libyan prime minister has left Tripoli and joined with rebels in the country's western mountains.
Abdel Salam Jalloud "is in Zintan and he is a free man among the rebels," said Jumma Ibrahim, a spokesman for the Military Council of the Western Mountain Region, a rebel group.
Kaim declined to confirm or deny the report.
Jalloud was among members of Gadhafi's inner-circle responsible for the 1969 coup that put Gadhafi into power. Jalloud fell out of favor with the regime in the mid-1990s.
The speculation over a Gadhafi "last stand" comes as his troops are battling rebel forces on a number of fronts, including in the west, where fighting has raged for days over the strategic city of Zawiya, about 30 miles west of Tripoli and a major supply route to the capital.
Fierce artillery fire could be heard around Zawiya on Friday. Rebels took a major oil refinery there, said Hobab Jomaa, a rebel fighter. They were in control of the western part of the city, but battles continued in the eastern part, he said.
When asked when rebels might begin their move toward Tripoli, one fighter in Zawiya told CNN's Sara Sidner, "Two days, maybe by the end of the week."
"They are becoming more emboldened," Sidner said of the rebels. "They feel like they can really have a chance at Tripoli."
The International Organization for Migration said Friday that it is working to evacuate an unknown number of foreign nationals from Tripoli and other western cities "who are increasingly vulnerable and now want to leave."
Government spokesman Musa Ibrahim downplayed the movements Friday, saying rebel supply lines have been cut off from the coast and from the south, rendering them unable to advance.
"We have paid a heavy price, and we have nothing in front of us except the prize, and the prize is victory over those traitors who collaborated with the crusader enemy and transformed Libya into a bloodbath," Ibrahim said.
Meanwhile, a NATO airstrike destroyed the home of Abdullah al-Sanussi, the head of Libya's intelligence service and a brother-in-law of Gadhafi's, neighbors and Libyan government officials said Friday.
The strike also destroyed a school and medical store, neighbors and officials said. One person -- not al-Sanussi -- was killed, they said.
In June, the International Criminal Court issued an arrest warrant for al-Sanussi along with Gadhafi and his son Saif al-Islam for actions taken as a popular uprising morphed into civil war.
The warrants are for "crimes against humanity," including murder and persecution committed in Libya in February "through the state apparatus and security forces."
Gadhafi's government has rejected the court's authority.
The attack on al-Sanussi's house followed a NATO airstrike Thursday night that killed a brother of Ibrahim, the government spokesman, a Libyan government official said.
Hasan Ali Ibrahim, a younger brother of Musa Ibrahim, was working as a civilian volunteer for the Gadhafi government, the official said. The 25-year-old university student had left Tripoli with a group of people to check on friends in Zawiya; he and the others were struck by bullets fired from an Apache helicopter while on foot in Zawiya's central square, the official said.
CNN's Ben Wedeman, Matthew Chance, Barbara Starr and Yasmin Amer contributed to this report.