President Mohammed Siad Barre of Somalia expressed confidence yesterday that "a new chapter of closer cooperation" lay ahead for his country and the United States, but suggested he was not satisfied with the level of American economic and military aid to his poor and strife-torn nation.

The African leader, whose country is viewed as strategically located by U.S. planners hoping to defend the Persian Gulf in an emergency, appeared at a press conference here after a series of meetings in Washington, including one yesterday afternoon with President Reagan.

Asked if he was satisfied with the level of U.S. aid requested by the administration, Siad Barre said that his meetings with Reagan, Secretary of State Alexander M. Haig Jr. and congressional leaders were "satisfactory, but the amount was not."

Siad Barre said that he really preferred not to answer such a question directly and that he wasn't complaining. His country needed more defense and economic help, he claimed, and needed it faster. But "the atmospherics were excellent" in his three days of meetings here and so he was "confident the future will be good."

The Reagan administration has requested roughly $90 million to $95 million for the next fiscal year for Somalia in a combination of military, economic and food assistance, plus aid for helping care for some 700,000 refugees from the disputed Ogaden region of Ethiopia, an area of chronic warfare between Soviet-and Cuban-backed Ethiopian forces and Somali guerrilla forces.

The new budget request is up from about $78.5 million from this year, but the Somali regime has been pressing Washington for a number of years now for vastly larger sums. Relations with Somalia have been improving since 1977, when the Somalis expelled Soviet advisers. In 1980, Siad Barre agreed to allow the U.S. access to ports and airfields if necessary in a military emergency.

Senior U.S. officials said the administration was considering a further boost in aid but that Siad Barre had made no specific requests and that no U.S. decisions had been made.

These officials said that Siad Barre was also certain to discuss the threat to his country and others in the region from Libya during the half-hour meeting with Reagan.

At the press conference, however, Siad Barre tended to play down the direct threat from the Libyans and their ruler, Col. Muammar Qaddafi. He said the Libyans try to disrupt the peace and stability of the region but "we are not so afraid of Libya. They have money but what else," meaning that Libyan military forces themselves were not much of a threat.

"The Soviet Union, the Cubans and East Germans," he said, are the real threat in the region. The Libyans give money, and others make use of it, Siad Barre added. He indicated that Americans "talk too much about" Libya, suggesting that such talk elevates Qaddafi's stature.

Following the meeting with Reagan, Siad Barre and Haig met with reporters. Haig said the Siad Barre discussions were "very productive."