Mayor Walter E. Washington said yesterday that the D.C. Department of Manpower would have to spend more than five times as much as it already does to reach all the 173,000 people in the city who need jobs and job-training assistance.

"With nearly 1 out of every 2 black teen-agers in this city without jobs, we cannot put off taking firm actions," the mayor told a luncheon audience on Capitol Hill. "We must move forward now to create jobs and expand the job market."

Additional job training funds would have to come from the federal government, the mayor said, because the city barely has enough of its own financial resources to "maintain mandatory services in most areas."

The mayor's speech to the Greater Washington Full Employment Action Coalition, a group of labor, religious and civic representatives was part of a week-long rallying effort aimed at gathering political support for federal action to increase employment opportunities.

Washington's reference to the city's high youth unemployment rate and the push for more federal funds echoed the concerns expressed by several national black leaders recently that the Carter administration had not committed adequate federal resources to combat the problems faced by blacks.

Last week, th Labor Department reported that unemployment among black youths across the nation during the summer was nearly 35 per cent, the highest ever recorded by the government. Yesterday, members of the Congressional Black Caucus met with President Carter and were told that the administratin would give reduction of the black youth unemployment rate a high priority.

It was the second time in less than a week that the mayor, who is beginning his 10th year in office and pondering running for re-election in 1978, mentioned jobs as a high priority for is own administration.

In an interview Sunday with the Washington Star - the mayor's first major interview in about a year - Washington said he planned soon to announce establishment of a job corps training program in the city.

That plan, now being formulated by mayoral assistant Joseph P. Yeldeil, would rely heavily on funds from the Labor Department, a mayoral spokesman said yesterday. The city has never had a job corps program before, the spokesman said.

The mayor said yesterday that the city is 30,000 jobs short of having full employment. The city economy would need 18,000 more jobs just to reach an unemployment rate of 3.6 per cent, the lowest level of the decade, he said. The current D.C. unemployment rate is 7.9 per cent.

Some city job-training programs have been hurt by high unemployment in the areas for which they train future job seekers. Progress in some apprenticeship and training programs have come to a standstill, the mayor said. In other job areas, increased hiring of women and minorities "has been curtailed," he noted.

The D.C. Manpower Department with an annual budget of $45 million, also has been plagued by internal problems. Last spring, a private auditor found that the financial records of 12 of the 14 programs that receive $12 million in job-training funds were incomplete and could not be audited.

Some teen-aged job seekers told The Washington Post last May that the Manpower Department's job finding office is ineffective. "I went down there when I got out of school and waited and waited just for someone to talk to me," one 19-year-old who graduated in 1976 said "And then all that happened was I filled out a form and I haven't heard anything yet."