MOSCOW, JAN. 11 -- The Communist Party newspaper Pravda today sought to put the burden on Washington to end the war in Afghanistan, saying the "crux of the matter is not a date for the withdrawal of Soviet troops but a date for stopping aid" to the U.S.-backed rebels.

The article, signed by an authoritative political observer, Vcevolod Ovchinnikov, brought the Soviet timetable for a settlement into sharper focus, indicating that Moscow wants to resolve the eight-year war before the U.S.-Soviet summit meeting here in the late spring. A resolution of the Afghan conflict would be "an important additional prerequisite" for success at that meeting between President Reagan and Soviet leader Mikhail Gorbachev, Ovchinnikov said.

The Pravda article is the first commentary in the Soviet press on developments surrounding Afghanistan since Foreign Minister Eduard Shevardnadze said last week that Moscow hopes to withdraw its troops in 1988. About 115,000 Soviet troops are in Afghanistan.

Ovchinnikov noted that if a round of U.N.-sponsored indirect talks between Afghanistan and Pakistan in Geneva next month proves successful, an agreement on nonintervention could be signed by March 1, to take effect May 1.

Repeating assertions made last week by Soviet diplomat Yuri Alexeyev, Ovchinnikov noted that the United States already is committed to cutting off aid to the Moslem rebels 60 days after the signing of an accord in Geneva. The Pravda article challenged U.S. claims that a cutoff of aid to the resistance fighters depends on the schedule and procedures for the Soviet pullout.

"It is enough to have a look at the documents already agreed upon in Geneva," Pravda said.

Ovchinnikov noted that almost the entire package of agreements in Geneva has already been negotiated and hinted that recent U.S.-Soviet talks have contributed to progress on the issue. "Contacts which the Soviet side has had with representatives of other states confirm that there are good international prerequisites for settling the Afghanistan situation and for ending outside interference in its affairs," he said.

Western diplomats here see the burst of Soviet diplomatic activity on Afghanistan this month as a sign that Moscow is now ready to withdraw its troops without assurances of the survival of the regime it supports in Kabul, headed by Najibullah.

By raising the issue of success at the next summit, today's Pravda article also indicates that Moscow will press the United States hard to stop its aid to the rebels as soon as the Soviet withdrawal begins.

"Evidently, all forces involved in the inter-Afghan conflict should understand: paving a way to reconciliation and nationwide concord, they also promote their own and worldwide interests," Ovchinnikov said.