The resolutions committee of the U.S. Conference of Mayors grudgingly faced the possibility yesterday that Congress may enact portions of President Reagan's plan to consolidate federal categorical aid programs into block grants controlled by the states.

The committee asked the administration and Congress to require governors and state legislations to channel the money to the needy and give mayors an "active role" in determining how the funds are to be spent.

In another action, the resolutions committee, citing news reports of billions of dollars wasted in defense programs, called on Congress to "redress the imbalance" between domestic and military spending and "recognize that the national security of this nation includes both the military defense and the social defense."

The block-grant issue has dominated the annual meeting here, sparking heated partisan clashes between Democratic and Republican mayors. Atlanta Mayor Maynard Jackson expressed the dominant fear of fellow Democrats about Reagan's plan for consolidating federal aid to education, health, energy and social services programs and shifting control over them out of Washington to the states.

"At best there are only four states -- Massachusetts, Michigan, Minnesota and California -- that have shown sensitivity on urban issues.The other 46 have shown either neglect or downright hostility," Jackson said.

The block-grant resolution came after pressure from Republican mayors to endorse the president's proposals. Democrats, who outnumber GOP mayors by about 3 to 1, resisted Republican efforts for outright endorsement of the plan but seemed to take the attitude that if Congress does approve block grants, then mayors ought to have influence and a role in saying how it should work.

Richard Carver, the Republican mayor of Peoria, Ill., accused his Democratic counterparts of showing "the height of hypocrisy" on the issue. He said they were happy about block grants for community development and job-training programs that the cities will control but were raising objections only to those programs that would be turned over to governors under the Reagan plan.

The Republicans had also tried to stop the resolutions committee from criticizing the growth in defense spending but after protracted debate and parliamentary maneuvering were unable to do so.

"If we do not maintain our cities and domestic environment we will have nothing to defend," said Lee Alexander, the Democratic mayor of Syracuse, N.Y. "We can look back to the 'smoking '60s when we failed to see that."

Richard S. Williamson, senior White House liaison to state and local governments, told reporters he believed the wrangling over the block-grant issue was "something of a smokescreen" thrown up Democratic mayors to mask their real concern over cuts in the budget.

Williamson told the conference committee that Reagan planned to continue to consult with mayors on proposals affecting them but that the president believed that block grants were the efficient way to allocate "shrinking federal resources."

He also noted the extent to which federal aid has been the consuming issue for mayors conferences by reading from old news clippings dating back to 1953 in which money has been a recurring theme.

"This is not a new refrain for them to be concerned about the federal dollar," Williamson told reporters.

"Every president since President Eisenhower has been attacked by the U.S. Conference of Mayors. They attacked Kennedy. They attacked Johnson, Carter. It's nothing new that they're now attacking President Reagan."