Secretary of State Alexander M. Haig Jr., heading into an unusually strained meeting with Soviet Foreign Minister Andrei Gromyko, early this morning denounced the latest statements from Warsaw as "a disappointment" and "essentially an effort to justify the continuing repression of the Polish people."

Haig's assessment of the speech by Gen. Wojciech Jaruzelski was announced in a hastily summoned midnight press conference by his spokesman, Dean Fischer. It appeared to be intended to maintain the diplomatic pressure against martial law in Poland as Haig prepared to meet his Soviet opposite number.

Yesterday Haig had a less forceful initial assessment of the Polish announcement, seeming to accept the prospective lifting of some aspects of martial law as a step in the right direction. But tonight he said the Warsaw statement made "no mention of genuine movement on martial law" and left "little hope for any serious move toward moderation and conciliation."

In Washington, White House deputy press secretary Larry Speakes said Jaruzelski's "speech surely could not be characterized as positive in its implications," if initial reports on its content are accurate.

The speech "appears to offer a strong defense of the martial-law regime, distorts the role of Solidarity and makes no promise that prisoners and detainees will be released," the White House statement said.

On behalf of the administration, Speakes said: "We're still waiting for the government to end martial law, to free those arrested as a result of martial law and to engage in meaningful dialogue with the (Catholic) church and Solidarity to restore human rights in Poland."

The Polish aspects of Haig's meeting with Gromyko here today were clouded by the Soviet minister's refusal, stated in advance, to discuss martial law in that country, the number one item on the American agenda.

"It could be a very short meeting then," Secretary of State Alexander M. Haig Jr. commented to reporters after hearing of Gromyko's public declaration, on arrival here, of unwillingness to discuss the Polish question.

Haig's aides announced a plan for four hours of talks of a "basically unstructured" nature, with either side free to discuss whatever it wishes.

Following the preliminary sparring by Haig and Gromyko in their conflicting arrival statements, most of the suspense is about how much public acrimony, rather than how much diplomatic harmony, might result from their discussions.

On his arrival Sunday night, Haig announced he would confront Gromyko directly with "the outrage" felt in the United States and the West at large about Soviet responsibility for events in Poland.

Gromyko, speaking at the same airport microphones Monday afternoon, declared, "I have no intention whatsoever of discussing questions relating to Poland or the domestic situation in Poland."

The Soviets have consistently declared that the "internal affairs" of Poland are not a subject for Soviet-American discussion.

In what seemed to be a bid for public approval, especially on the political battleground of Western Europe, Gromyko also said on arrival that he is prepared to do his best "to promote agreements and understandings in those areas where such possibilities do exist."

The U.S. side has ruled out using the current talks to launch a new round of strategic arms negotiations as previously expected, but U.S. officials said they expect Gromyko to raise the subject.

According to the State Department, Haig and Gromyko will meet for two hours this morning at the U.S. mission here and for two hours this afternoon at the Soviet mission.

The meetings were originally scheduled to run for two days but were cut back by the United States in disapproval of eventas in Poland.