Nancy Reagan and the wives of 17 foreign leaders tiptoed through the mine fields of illicit drug production and trafficking yesterday at the first of a two-day White House "summit" conference by avoiding any discussion of how their governments might disagree.

The closest Mrs. Reagan came to the subject was after the last limousine had pulled away from the South Portico and she paused to talk to reporters. Asked about an unrelated State Department report that says some of the countries at her conference are not doing enough to control cocaine production and exports, she said: "Well, in a lot of the countries who are exporting, the governments do try to stop it and sometimes tragedies occur."

At another point, when asked if she was trying to change her husband's mind about cutting federal funds for drug-abuse programs, she replied that her focus is different.

"I'm talking mother-to-mother," she said. "I don't get into the other."

Asked if there had been any surprises during the day from her guests, Mrs. Reagan said, "No, not really . . . Their countries are just beginning to be aware of drugs, how far behind they are and how thirsty they are for knowledge and help and advice."

She said she did not know how the first ladies were chosen to be invited to attend. "Obviously we couldn't invite everybody. I obviously don't know."

One of the day's more emotional moments came during the morning session when a 16-year-old reformed drug addict, Robin Page of Cincinnati, told the first ladies how after being hospitalized for an overdose she lay there thinking, "Don't let me wake up. I just can't see her mother's face again."

Nancy Reagan brushed away a tear and Italy's Anna Craxi was near tears as they listened to Robin's story of how she used marijuana, alcohol and amphetamines for two years before her parents finally forced her to enter the Straight drug-treatment program.

"Most people my age aren't mature enough to say, 'I need help, help me,' " Robin told Canada's Mila Mulroney, who wondered how much of a role guilt played in her refusal to admit she had a drug problem.

Coincidentally, a Senate appropriations subcommittee yesterday called for a $53 million increase in the Drug Enforcement Administration's fiscal 1986 budget and for an additional 300 drug enforcement agents and 200 support personnel. The Office of Management and Budget has cut DEA's request to a $9 million increase for a budget of $345.7 million, with 134 new positions.

"We are clearly not winning the war against drugs," Sen. Alfonse D'Amato (R-N.Y.) said, referring to a Justice Department report that says the use of cocaine, heroin and PCP is on the increase.

To the cadence of the Old Guard Fife and Drum Corps, the first ladies were greeted at the South Portico by Mrs. Reagan. She wore a white Adolfo suit with navy and burgundy trim; some of her guests, such as Malaysia's Siti Hasmah, Mauritius' Sarojini Jugnauth and Pakistan's Shafiq Zia-ul-Haq, wore their national dress.

Mrs. Reagan had handshakes for some of the women and hugs for those she already knew, such as Mulroney, Ireland's Joan FitzGerald, Craxi, Japan's Tsutako Nakasone and Jamaica's Marie Elizabeth Seaga.

The group met President Reagan in the Blue Room a few minutes later, then filed into the East Room, where they sat at a U-shaped table, each wearing earphones to hear one of the seven languages being simultaneously spoken.

The life-size portraits of George and Martha Washington were all but hidden by translators' booths, electronic equipment and other accessories without which no respectable international conference would convene. And, predictably, there were some minor snafus when headset controls didn't always match language dialed.

"I was a little distressed," Mulroney began at one point when the sound went dead, leaving the audience forever in ignorance of what had distressed her. Another time, a translator was heard to complain to a colleague, "I cannot hear the first lady."

U.S. government officials briefed the women during the morning session on national and international aspects of the drug-abuse problem; the afternoon was devoted to presentations by representatives of parent groups, pharmacists, the media and community service organizations.

At times the morning session sounded as though it were as much a testimonial to Nancy Reagan as it was a skull session for trading ideas and searching for what she called "a common understanding among nations of the drug problem."

"She has been our point man in this fight," said Carlton E. Turner, deputy assistant to the president for drug-abuse policy and one of those to whom Mrs. Reagan turned for guidance and advice when she launched her drug-abuse program.

Assistant Secretary of State Jon R. Thomas said the first lady's "example and commitment . . . resulted in worldwide focus on an international problem which, in the past, has received too little attention."

At both sessions, many of the first ladies had questions and observations.

Eugenia Cordovez Ponton de Febres-Cordero of Ecuador, a major transit area for U.S.-bound cocaine, said that while consumption is not yet a major problem in her country, production is. Describing how authorities have destroyed coca bushes and 631 kilograms of cocaine, she said, "I am not ashamed to say this . . . It is our duty to share information with others here."

Marianne von Weizsaecker of West Germany, citing unemployment as a major problem, said there aren't any easy answers for West German youth who "go through a complicated education program, then find out that they are not being used in life."

Nancy Reagan seemed to disagree.

"I suppose employment is a factor," she said, "but I don't believe it's the main factor. There are lots of well-employed people involved in drugs."

Zia-ul-Haq of Pakistan, where opium production is substantial, told of "doing our best" to destroy crops.

"My husband is doing his level best. We have not been able to fully control it," she said, speaking in Urdu through an interpreter.

Thomas, who had pointedly steered clear of placing blame in his opening remarks about the worldwide drug problem, regained the microphone.

"Pakistan has made outstanding progress against opium production, thanks to the firm resolve by your husband," said Thomas, noting that Pakistan "may serve as a useful model" as the result of a United Nations assistance program.

Teresa Ormachea de Siles of Bolivia, where a U.S. congressional report says coca production may be responsible for 40 percent of the international cocaine traffic, said 90 percent of her country's war against drug trafficking has occurred in the last five years. Through seizure and search operations, she said, "there has been an atmosphere of democracy and freedom."

Rosa Elena Alvarez de Betancur of Colombia, the source of an estimated 75 percent of the cocaine entering the United States, defined the drug problem as "one of the great epidemics in the world."

Seaga of Jamaica, which provides the United States with between 2,000 and 4,500 metric tons of marijuana each year and is a transit point for smuggling Colombian-produced cocaine, did not raise Jamaica's drug problems.

She focused, instead, on Page's drug experiences and "on how important it is to take an interest in children's lives and not let the kids be afraid of us. Mothers here must go back with the message."

Mulroney called peer pressure one of Canada's biggest problems in combating drug use among youth. Portugal's Maria Manuela Eanes said she thought it important "to make sure television supports the human values" and that there also be "useful activity for children in their leisure time."

Japan's Nakasone wanted U.S. officials at the conference to tell her what kind of an international program would be the most desirable in curbing the drug problem.

Thomas told her the "primary effort" should be reducing supplies at the source.

"Through supply reduction, we feel that will benefit all of our societies," he said.

FitzGerald said she looked forward to the day when liquor commercials, like those advertising cigarettes, would be banned from television in Ireland, where the liquor industry plays a major role in the economy. She said smoking has dropped appreciably since television advertising of cigarettes was stopped.

West Germany's von Weizsaecker asked how anybody could be certain that Nancy Reagan's drug-abuse commercials and similar efforts haven't reached a "saturation point."

Mrs. Reagan replied that "we're just beginning to see more people coming forward."

Today, Nancy Reagan and her guests fly to Atlanta to attend a conference sponsored by the Parents Resource Institute for Drug Education (PRIDE). Its international work in drug abuse has commanded the attention of several countries represented at Mrs. Reagan's summit.