The D.C. Department of Human Resources cannot pay the costs of longer sentences and better rehabilitation services for dangerous juvenile offenders that a Superior Court judge has recommended, acting DHR director Albert P. Russo said yesterday.

But D.C. Suerior Court Chief Judge Harold H. Greene, who made the recommendations, says he wants the stiffer sentencing program to begin anyway.

"I personally am not prepared to wait until the money (for improved DHR services) is obtained. The program will be started," Greene said in a telephone interview yesterday.

Greene last December urged other Superior Court judges to begin sentencing repeat juvenile offenders to at least two years for convictions of rape, murder, armed robbery and other serious crimes as of Feb. 1.

He also called for better rehabilitation programs at the D.C. Children's Center operated by DHR in Laurel, Md., where juveniles are confined.

Russo said at a news conference that DHR needs more guards, social workers, psychiatrists and other staff to comply with the stricter juvenile code. Money for those additions may not available for two years, Russo and other DHR officials said.

The first youths committed to Laurel under Greene's recommendation are expected to arrive next month, according to Superior Court social services official Aurora McDonough.

Greene said he has agreed to support any DHR Council or Congress, but in the meantime, has "no intention of simply holding up the program." The purpose of stiffer sentences is "to protect the community from these dangerous juveniles," he said.

DHR has not estimated the cost of meeting Greene's proposal and may have to wait until fiscal year 1979 for the needed funds, according to DHR official James D. Butts.

Another Greene recommendation - already implemented - calls for better screening of juvenile defendants to weed out less serious offenders who may not warrant full prosecution. As a result, the number of juvenile trials has undergone a "considerable reduction" in recent months, McDonough said.

Russo said the number of youths awaiting trial at the Laurel facility has dropped from about 400 to 300 because of the pretrial screening.

Serious offenders comprise about 4 per cent of the nearly 3,000 cases handled each month by the city's juvenile justice system, according to McDonough. The average period of incarceration for offenders in general is about nine months.

Under Greene's plan, serious offenders at age 17 or older would receive the maximum legal sentence of two years on their second conviction. The terms could be held longer - until age 21 - if the sentencing judge determines that rehabilitation has not been complete in the two years.