White House officials acknowledged yesterday that they had issued confusing statements about the skin cancer that was removed from President Reagan's nose last Tuesday, but insisted that no deliberate attempt had been made to deceive the public.

Answering questions at an unusually acrimonious briefing, White House spokesman Larry Speakes said the information given reporters was incomplete and sometimes "confusing," but said he had been truthful in his responses.

"You pulled an iron curtain down on the truth," senior White House correspondent Helen Thomas of United Press International said.

"Exactly right," Speakes replied. "But I did not lie and I told the truth."

Informed sources said that the "curtain" Thomas referred to had been drawn at the order of Nancy Reagan, who last Thursday instructed White House chief of staff Donald T. Regan, Speakes and her own aides to limit the information about the growth removed from the president's nose.

These sources said that it is not clear how much Mrs. Reagan knew about the medical findings at the time but pointed out that a preliminary report received at the White House on Thursday indicated that the growth was cancerous. A more complete report was received Monday.

The president disclosed at a meeting with reporters Monday that the removed growth was "the most common and least dangerous" type of skin cancer and would not require further treatment. He said he had not known until the weekend at Camp David that the growth was even being tested for cancer.

Speakes said in an interview yesterday that "once the president had the full facts on the biopsy he was anxious to explain it himself and wanted to do it in an opening statement, but decided instead to wait for a question." Reagan would have volunteered the statement if he had not been asked, Speakes said.

Reagan's comments Monday raised questions among reporters about the credibility of Speakes and especially of Jennefer Hirshberg, Mrs. Reagan's press secretary.

During an angry confrontation yesterday morning with Sam Donaldson of ABC News, Speakes maintained that he had told the truth and said, "You want to call me a liar? You want to?"

"I haven't called you a liar," Donaldson replied. "Questions of your credibility have been raised."

Speakes told reporters last Thursday that a biopsy to check for cancer would be routinely performed. Later in the day a statement was issued from the press office, without Speakes' name on it, saying that the tissue "was submitted for routine studies for inspection and it was determined that no further treatment is necessary." The statement did not mention either a biopsy or that the cancer was found.

On Friday, Speakes declined to answer questions about the biopsy, but Hirshberg told UPI that Mrs. Reagan had said that no biopsy had been performed. A White House official acknowledged that another member of Mrs. Reagan's staff told a reporter the same day that the removed growth was not cancerous. On Monday, Hirshberg told The Washington Post that neither of the Reagans knew of the biopsy until they were told the results over the weekend. She was unavailable for comment yesterday.

Privately, White House officials said that Speakes had walked a tightrope between the desire of Mrs. Reagan to have as little information released as possible and his recognition that reporters are intensely interested in any medical treatment of Reagan since the removal of a cancerous tumor from the president's colon last month.

"Everything is different now," one official said. "People will be interested if the president has a cold."

Recognizing this, both Speakes and chief of staff Regan were said to have recommended full disclosure of the facts about the removal of the growth from the president's nose. Their counsel went unheeded, said one source, who said Mrs. Reagan was concerned that confirming removal of even a minor cancerous growth could lead to "scare stories" about the president.

One official said that aides' response to questions about the growth on the president's nose had "taken the luster off" the performance of the White House in the days after the removal of the president's colon cancer. After the colon operation, White House officials and Reagan's physicians disclosed more information than had ever been made available after surgery on a president.

An official said yesterday that this candor gave credibility to the White House effort to dramatize Reagan's recovery through release of a carefully timed series of photographs and other well-orchestrated events.

Withholding information after the far more minor nose surgery produced an opposite effect. One official, reflecting on the past week with misgivings, said "it should provide a lesson learned" for the Reagan presidency.