Senator Claiborne Pell (D-R.I.) urged the White House yesterday to cut off all U.S. economic aid to Afghanistan indefinitely and to refuse to appoint a new ambassador to Kabul until the Afghan government apologizes for its role in the killing last week of Ambassador Adolph Dubs.

Accusing the Afghans of demonstrating "gross insensitivity and rudeness" in rejecting a U.S. note of protest, Pell said that the Carter administration should also withdraw the 30 to 35 Peace Corps volunteers currently in Afghanistan and reduce U.S. embassy personnel by half.

Dubs was shot and killed when Afghan police accompanied by Soviet advisers stormed the Kabul hotel room where the ambassador was being held hostage by Afghan gunmen on Feb. 14.

Characterizing the protest note as "no more than a slap on the wrist," Pell, a former Foreign Service officer, said, "We must not supinely accept an outrageous action by a third-rate power that has already made clear in so many ways that it is no friend of ours."

Pell made the demands in a letter to President Carter and reiterated them in a statement on the floor of the Senate.

At the daily White House briefing yesterday, press secretary Jody Powell confirmed a report in The Washington Post that current aid levels to Afghanistan are being "severely reduced" and a proposed military training program is being canceled as result of the new tension between Washington and Kabul.

Powell said that the fiscal year 1980 request for $17 million in economic aid would be pared to a much smaller amount for allocation to only the neediest Afghans. The military training program was budgeted for $310,000 next year.

Pell said the Afghan government should accept "full responsibility" for Dubs' death and provide adequate protection of the U.S. diplomats there. In asking that the U.S. embassy personnel be reduced by half, Pell said that the administration should tell the Afghans also to reduce their embassy staff in Washington by the same proportion.