White House Chief of Staff Howard H. Baker Jr. said Wednesday he is "reasonably hopeful" that the United States will succeed in removing Panamanian ruler Manuel Antonio Noriega from power.

Baker spoke with reporters one day after President Reagan said at a surprise news conference that he will not strike a deal that would "whitewash anyone" in Panama.Both the president and his chief of staff declined to discuss reports that the United States has offered to drop drug trafficking charges against Noriega.

"The negotiations are under way," said Baker. "Our policy is that Nor-iega must go and indeed that remains our commitment."

He said he did not know how the negotiations would be affected by Tuesday's 86-10 vote in the Senate for a non-binding resolution expressing opposition to any negotiations for a deal that would involve dropping the indictment.

"I understand the frustration that was expressed by the Senate and I am sympathetic to that," said Baker, a former Senate Republican leader.

"The fact remains that the administration has a firm, fixed policy that Noriega must go and we are working very hard to see that that happens. We're working very hard to see that that happens. I am reasonably hopeful that we'll get that result, but we don't have it yet."

"The idea of indicting the leaders of foreign governments is fairly new," Baker said. "It's not one of the traditional instruments of foreign policy. But it certainly is something that has had a concentrating effect on Noriega's mind, apparently, so by whatever means, we're going to use that to our advantage to try to implement administration policy, which is to see that Noriega leaves power, leaves the country, and paves the way for democratic rule in that nation."

Questions about Noriega and embattled Attorney General Edwin Meese III dominated Reagan's meeting with reporters Tuesday. Reagan also said no decisions were made at the White House on the basis of astrological advice to first lady Nancy Reagan.

When asked whether he believed in astrology himself, however, he paused and replied, "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 or not."

Of Meese, the president said, "I think that there's been a wave, and for quite a long time . . . in which accusation or allegation is taken to mean conviction. And there's been too much of that."

"I think that for him to step aside would be what he himself once said - that he would then live for the rest of his life under this cloud - with nothing that had ever been proven."

The Justice Department has been rocked in recent weeks by unrest and resignations stemming from criminal investigations of Meese's affairs.

On Panama, 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, Reagan said, "It would be foolish to do so. Some things you have to keep to yourself when you're arguing with someone else."