WASHINGTON (AP) _ President-elect George Bush and his staff are defending the way the transition office has handled appointments in a week that produced only one announcement.

All week, there was speculation that Bush would make announcements on more Cabinet members, particularly for the defense department and other national security jobs. But the only statement was that Marlin Fitzwater would stay on as White House spokesman.

Bush, who met Friday with foreign leaders and former presidential rivals, including Michael Dukakis, seemed to bristle when reporters asked him if his appointment process was stalled.

''There's no holdup. We're way ahead of schedule,'' he said, complaining about ''early, premature, needless speculation.''

Craig Fuller, co-director of the Bush transition office, said Bush and his aides spent part of the past week talking to experts in defense and national security about running the mammoth agency.

''The whole point of this week has been designed to try to explore how best to manage the Defense Department, what kind of challenges await the next secretary of defense,'' he said.

Fuller said former Sen. John Tower of Texas remains a contender for the job, and the vice president has ''tremendous confidence'' in his old friend.

Though Fuller said nothing to dispel reports that Tower is the leading candidate for defense secretary, he added, ''There may be others, there may be other approaches.''

Fuller also said Bush is taking an overview of his Cabinet vacancies because he wants to make sure women and minorities claim some of the top jobs. To date, only white males have been named to the positions, although Lauro Cavazos, a Hispanic, has been asked to stay on as education secretary.

Fuller said it could be a couple of weeks before the Cabinet is in place, but appointments will be made as they are decided upon.

Meanwhile, The Washington Post reported today that Bush has decided to remove from Cabinet rank the job of ambassador to the United Nations and not to restore to Cabinet level the director of the Central Intelligence Agency. The paper quoted transition officials as saying the decision reflects his belief that the two posts - both of which he has previously held - should be less visible in internal policy-making debates.

Bush and Dukakis met for 35 minutes Friday, and the two avoided the negative rhetoric that characterized the presidential campaign.

''I expressed my concern obviously about the deficit,'' Dukakis, the former Democratic candidate, said. He also stressed issues that were important to Democrats - better health care, housing, education and the environment.

Bush said afterward: ''I want to express my appreciation to Governor Dukakis for coming our way. We had good discussion of the issues that are facing the country in a spirit of good will.''

The vice president also saw Pat Robertson, who tried unsuccessfully to gain the GOP presidential nomination. Robertson said he talked with Bush about South Africa, a country the television evangelist recently visited.

''The time has come to recognize the South African government needs a little encouragement,'' said Robertson, an opponent of sanctions and disinvestment as a strategy for forcing change in the white-ruled country.

Late in the day Bush met at his residence with Argentine President Raul Alfonsin, who had flown in from New York for the get-acquainted session.

Neither Alfonsin nor Bush commented on reports from Argentina that troops had moved into position to quell an insurrection at a military base outside Buenos Aires.

The government said later it had put down the rebellion.

Vice President-elect Dan Quayle, Secretary of State George Shultz, Treasury Secretary Nicholas Brady and Assistant Secretary of State Elliott Abrams attended the meeting.

Bush began his day seeing Bermuda Premier John Swan, the fourth foreign leader he has met since he was elected. Alfonsin was the fifth, and Soviet leader Mikhail S. Gorbachev will be the sixth.

Bush will join President Reagan at a meeting with Gorbachev in New York on Dec. 7.

So far, Bush's only scheduled event over the weekend is to attend a movie entitled ''My Stepmother is an Alien'' on Saturday night. The Bushes usually attend church on Sunday.