Libyan leader Muammar Qaddafi spoke today of his increasingly violent confrontation with the United States in the Gulf of Sidra as a matter of "war."

Qaddafi said he has no interest in talking to the Reagan administration at this point. "It is not a time for speaking. It is a time for confrontation -- for war," Qaddafi said. "The Gulf of Sidra is ours."

"If they the United States want to expand the struggle, we will carry it all over the world," Qaddafi warned.

But the conditional language he used, putting the burden of escalation onto the Reagan administration, suggested that Qaddafi may still be holding back from any precipitous action -- at least with conventional tactics.

Qaddafi made his remarks to reporters while touring a trade fair here this afternoon amid throngs of students and other supporters, who were waving their fists and chanting anti-American slogans. The Libyan leader often appears to relish the hatred and anger he inspires in Washington and today seemed visibly buoyed by the most recent turn of events.

His remarks came after reports that for the second day in a row U.S. Navy jet fighters had bombed Libyan antiaircraft missile installations at the town of Surt and attacked Libyan patrol boats.

The Reagan administration, intent on challenging Libya's efforts to claim the entire Gulf of Sidra as its territorial waters, began the air strikes yesterday after Libyan missiles were fired at U.S. aircraft on maneuvers inside the gulf.

Despite reported mass demonstrations here and in Benghazi today, the capital showed no sign of preparations for an expanded fight. Lights were on this evening and the streets had no less traffic than usual. The airport was open and flights appeared to be running on time.

Libya made no claims today, as it did yesterday, to have shot down American aircraft. It was not clear here whether any attempts were made to fire on American planes today with Soviet-made SA5 and SA2 missiles from the batteries that were attacked. In Washington, U.S. officials said the Libyans had not launched a second round of missiles.

But Libya's official radio station continued to raise the possibility, often threatened by Qaddafi in the past, that "suicide squads" or other forms of terrorist action might be used in retaliation against the United States.

In a broadcast monitored in London, official Libyan radio said, "The oil which America exploits and usurps should now be destroyed. The American bases in the Arab homeland should now be stormed.

"American spies who were pushed forward as experts and consultants should be executed, wherever they might be in the Arab homeland," it said, according to The Associated Press.

Although the immediate cause of the present conflict between the Reagan administration and Qaddafi is the issue of navigation rights in the Gulf of Sidra, it is the long-standing charge that Qaddafi is a key supporter of international terrorist activity that has led to growing hostility, first rhetorically and now militarily, by Washington.

The crisis dates back to the aftermath of terrorist attack on the Rome and Vienna airports last December. The Reagan administration accused Qaddafi of aiding and abetting the Palestinian who carried out the raid.

In January, the Reagan administration forcefully restated an order in effect since 1981 that Americans working here should leave. Many did, largely because of fear that the United States was preparing for some sort of military confrontation with Qaddafi. A State Department spokesman in Washington said current U.S. estimates are that there are as few as 100 Americans in Libya, the AP reported.

At the same time the Pentagon began a series of large-scale naval maneuvers in the southern Mediterranean near the Gulf of Sidra. During similar maneuvers in 1981, American planes had shot down two Libyan jet fighters sent to intercept them.

This time Qaddafi warned that the region just north of the 32nd Parallel at the top of the gulf would be a "line of death" for any U.S. forces that attempted to cross it.

For the past two months, American ships have approached the line without crossing it. This week they moved well inside to challenge Qaddafi's claim to anything beyond a 12-mile limit.

Throughout the exchanges during the past three months, Qaddafi conveyed a conviction that he was winning the respect of the Arab world and other developing nations.

Many moderate and conservative Arab governments are suspicious of the Libyan leader's revolutionary philosophy and his international ambitions. But because it is difficult for even moderate Arab states to condone an attack by an outside power on any Arab state, virtually all of the Arab world has supported him verbally in his confrontation with Washington and rejected what it terms U.S. aggression here.

Last fall the Libyan leader had found himself isolated from most of his neighbors and worried by increasing signs of discontent domestically. Members of his own armed forces reportedly have made several attempts against Qaddafi's life in the past three years.

But in recent weeks Qaddafi has shown signs of improving relations even with some of his most hostile Arab adversaries. At the end of January he met with Algerian President Chadli Benjedid for the first time in three years.

The effect that Washington's challenge and its actions during the past two days will have on Qaddafi's relations with his Army is unpredictable. But earlier in the year, many diplomats here believed that a fight against American forces on a limited scale would only serve to unite the armed forces behind Qaddafi.

Meanwhile, he continues to demonstrate his interest in exploiting the international media attention generated by his showdown with the Reagan administration.

Although under normal circumstances journalists only rarely are admitted here, both in January and today the Libyans welcomed them. Scores of reporters and camera crews have arrived here in the past 24 hours.

John Cooley, a consultant with ABC News and author of a biography of Qaddafi, said after seeing Qaddafi this afternoon: "He's on an all-time high now. This has really pumped the adrenalin into him."

Cooley noted that Qaddafi strode through the crowds at the trade fair today with very few bodyguards or security personnel apparent. Having watched Qaddafi's career since its beginning, Cooley said that what struck him today is "what good form he is in. I haven't seen him like that for years."