BOGOTA, COLOMBIA, DEC. 21 -- President Cesar Gaviria today denied that his government has negotiated a deal with the nation's drug barons and urged the international community to give his new anti-narcotics policy a chance to work.

In an interview, Gaviria, 43, vigorously defended his controversial policy of offering reduced sentences to traffickers along with the promise that they will not be extradited to the United States for prosecution if they surrender and confess to at least one crime. He described his policy, announced in September, as a solution to the drug problem within the framework of Colombian justice.

"We are as committed as we ever were to the fight against drug trafficking," Gaviria said in his office at the presidential palace.

Gaviria, who took office Aug. 7, also pointed to recent moves by his government to strengthen the judicial system to allow traffickers to be tried in Colombia. He said these measures will reduce reliance on extradition, which will be retained as a secondary instrument in the drug war.

Law enforcement officials in Colombia and abroad have expressed concern about recent signs that Gaviria may have softened his stand in the U.S.-backed campaign against drug trafficking. They have pointed to public exchanges of statements by the government and by leaders of the Medellin cocaine cartel as signaling a weakening of Colombian resolve.

Although the United States has not publicly criticized the government, U.S. officials have long described extradition as essential. They have cited the traffickers' record of killing, bribing and intimidating Colombian judges.

Gaviria campaigned as a hard-liner against the drug barons, and his government has been stung by the criticism of his drug policy.

Among the changes cited by Gaviria in the way Colombia will deal with drug and terrorism cases were creation of special secure courts in five cities, assignment of 82 anonymous judges to such cases and establishment of witness protection programs. In addition, he said, a special police force -- rather than judges -- will carry out the investigations and present evidence. These moves are to begin Jan. 16.

"Investigations will no longer be in the hands of defenseless judges, but in the hands of investigators with adequate protection," Gaviria said. "We will have many fewer judges who are much better protected. So we can begin to guarantee that people who commit crimes receive the punishment they deserve."

He added, "Given the immense effort and sacrifice by Colombia in recent years, we have the right to ask the international community to give us a margin of credibility and confidence to show we can strengthen our justice system.

"Internationally we are seen as lowering our guard on drug trafficking," Gaviria said. "In Colombia, if there are not bombs, if judges and policemen are not dying as they were in the first half of the year, immediately there is distrust. . . . I give you every guarantee that Colombia has the same policy against drug trafficking and the same commitment to the international community. . . .

"I would like to state clearly the government has made no political offer to the traffickers -- and no peace offer. We are using plea bargaining to face the problem of drug trafficking."

Gaviria cited the surrender Tuesday of Fabio Ochoa Vasquez, reputedly a leading figure in the Medellin cartel, as evidence that traffickers have been hard-hit by law enforcement agencies and that his policy is working. "That is the only way to explain the fact that a boss of that stature would surrender to Colombian justice," Gaviria said.

Ochoa, who has been indicted in the United States on charges of drug trafficking and planning the murder of a Drug Enforcement Administration informant, surrendered to Colombian authorities under a government decree guaranteeing that he will not be extradited and that he will receive reduced sentences for any crimes to which he confesses. Ochoa, 33, was the first prominent alleged trafficker to turn himself in since Gaviria's Sept. 5 announcement of his new anti-drug policy.

The president said the main guarantee that drug barons who surrender, such as Ochoa, will receive stiff sentences is international cooperation in providing evidence. Under Gaviria's decree, evidence presented by the United States and other countries will be admitted in Colombian courts.

"I am confident Colombian justice will give Mr. Ochoa the sentence he deserves for the crimes he confesses to and that are eventually proved with the help of U.S. authorities," Gaviria said.

The president said he expects more drug barons to turn themselves in, ending the wave of narcotics-related terrorism that has claimed more than 1,000 lives in the past 16 months. Three presidential candidates were among those killed.

Gaviria, who announced his new policy less than a month after taking office, said he had fully supported former president Virgilio Barco's all-out war on traffickers, but he added that political backing for extradition has weakened rapidly.

"I felt there had to be a solution based on Colombian justice," Gaviria said. "One cannot indefinitely face terrorism and have the only defense be the judicial system of another country."

The president said that prisons where traffickers are held will not be luxurious, as some officials have charged. But, he added, they will have to be sufficiently secure to prevent attempts to kill those who surrender because the government has an obligation to protect suspects' lives.

"The new policy of Colombia, while debatable, is a policy based on strengthening the Colombian judicial system," Gaviria said. "The international community, instead of being worried and untrusting because there is no terrorism in Colombia, should be satisfied."