Black nationalist leader Sam Nujoma said here that while it still "might be possible" to arrange a cease-fire in the South African-administered territory of Namibia (Southwest Africa), his main concern now is to intensify the guerrilla war there and liberate the cuntry by force.

Expressing confidence that his guerrillas could eventually win a war against South Africa, Nujoman said at a news conference that his Southwest African People's Organization (SWAPO) intends to "seize power" either onthe battlefield or through supervised elections and then set up its own "people's government."

Nujoma rejected any coalition with the South African-sponsored Democratic Turnhalle Alliance or any other black party inside Namibia. He said SWAPO had not fought a guerrilla war since 1966 in order to form a coalition govenment.

"We don't have the intention whatsoever of forming a coalition government with a branch of the South African fascist forces," he said, referring to the alliance, a grouping of white and black leaders.

The graying, bearded nationalist guerrilla leader seemed eager to portray himself and SWAPO as willing to go for a military victory rather than accept South African terms for U.N.-supervised elections.

Suth Afica and SWAPO have both been engaging in brinksmanship and hardening their lines as the proposed March 15 date for a cease-fire and arival of U.N. peacekeeping forces nears.

Nujoma said he had not yet received a letter from U.N. Secretary General Kurt Waldheim calling for a cease-fire March 15 and for U.N. peacekeeping forces to arrive the same day.