WASHINGTON--President Reagan refused to say yesterday whether he had approved the dropping of drug charges against Panamanian ruler Manuel Antonio Noriega and defended embattled Attorney General Edwin Meese III, saying his longtime friend would live "under this cloud" if he resigned.

Reagan said he had "complete confidence" in Meese, whose Justice Department has been rocked by unrest and resignations and who is the target of criminal investigations of his affairs.

At yesterday's brief news conference, the president also said, "I don't guide my life" by astrology but he did not disavow believing in it.

Reagan said no changes were ever made in his schedule because of astrological forecasts, as former White House chief of staff Donald T. Reagan has claimed in a recently published book.

"We made no decisions on it and we're not binding our lives to this," Reagan said. "And I don't mean to offend anyone who does believe in it or engages in it seriously," Reagan added.

Asked if he believed in astrology, Reagan paused a long moment, and said, "I don't guide my life by it, but I won't answer the question the other way because I don't know enough about it to say, is there something to it."

Questions about Noriega and Meese dominated the nationally broadcast question-and-answer session in the White House briefing room. It was his most extensive meeting with the press since a news conference Feb. 24.

There have been numerous reports that Reagan has offered to drop drug-trafficking charges against Noriega if he would leave Panama at least until after elections are held.

"We are in the midst of real negotiations. I can't comment further on this," Reagan said. Repeatedly, he said he would not reveal what the United States was offering Noriega while the negotiations were continuing but promised to make "a full statement" to the public "at the appropriate time."

However, Reagan said much of what has been written about the negotiations had been "based on some kind of leaks or misinformation, because there are no facts to sustain it."

In refusing to discuss the negotiations with Noriega, Reagan said, "It would be foolish to do so. Some things you have to keep to yourself when you're arguing with someone else."

"There has been no decision made on some of the things that are being discussed," he added.

"You're asking me to into what's being talked about, and I can only tell you that we're not going to white-wash anyone," he said.

Reagan also defended the administration against allegations that it knew long ago that Noriega was involved in drug trafficking but chose to look the other way.

"There had been some rumors...but no one ever received or could get evidence to substantiate those rumors," the president said.

The president gave a warm endorsement of Meese, his friend of more than 20 years who is under increasing pressure to resign.