The Moscow-backed regime says it has armed 30,000 supporters in Kabul and thousands more in outlying towns so they can defend themselves against a guerrilla onslaught when the Soviet pullout is complete.

In Moscow, a Foreign Ministry official said Tuesday that about 15,000 Soviet soldiers had been killed in Afghanistan, nearly 2,000 more than the Kremlin reported in May, when the Soviets last gave a figure.This indicated heavy losses during the withdrawal, but the official, Yuri K. Alexeyev, said: "It doesn't mean that during the last months we had the bloodiest period of the war in Afghanistan."

In the Pakistani capital of Islamabad, crewmen refused to fly a jet transport packed with 32 tons of food and medicine to begin the U.N. airlift to Kabul, a U.N. official said Wednesday. The crew decided that security in the beseiged Afghan capital was uncertain, said the official, Rene Albeck.

With the deadline for a Soviet pullout only a week away, members of the ruling party "have been armed to defend their homes," neighborhoods and towns, Foreign Ministry spokesman Nabi Armani said Tuesday.

"Party members look on their weapons as their pride," he said.

Amani said 45,000 additional party members who had finished compulsory military service volunteered for reserve duty or for self-defense and border units. They include 5,000 women assigned to non-combat units, he said.

President Najib told commanders of tribal and militia units Tuesday that once the withdrawal of Soviet forces is complete, "you are now on your own feet defending your free-born and beloved motherland," the British Broadcasting Corp. reported.

The BBC quoted Najib as saying "extremist" foes were not ready to give up the "selfish interest of themselves and their foreign supporters."

Afghanistan has been torn by civil war since an 1978 communist coup prompted a Moslem insurgency. Soviet troops intervened a year later, replacing one pro Moscow regime with another.

The Soviet withdrawal began May 15 and is to be complete by Feb. 15 under a U.N.-mediated agreement. However, Kremlin officials have said all Soviet forces would be gone by the end of this week.

In Moscow, Foreign Ministry spokesman Gennady Gerasimov told a news briefing Tuesday that food supplies had improved in Kabul, but the fuel shortage was critical. Soviet aircraft began an emergency airlift of flour and fuel last month.

The guerrillas and many Western analysts predict Najib's government will collapse soon after the Red Army leaves. The president says his conscript army is strong enough to defeat the insurgents.

Only about 1,000 Soviet soldiers remain in Kabul, guarding the airport, and Soviet officials said the last Red Army convoys would be out of the country this week.