President Reagan announced on the eve of Veterans Day that he will support creation of a Cabinet-level Department of Veterans Affairs, surprising leaders of veterans groups who went to the White House yesterday hoping to sell him on the idea.

Reagan, who pledged in the 1980 presidential campaign to shrink government by eliminating the departments of Education and Energy, made the announcement in the Cabinet Room with leaders of major veterans organizations and members of Congress who serve on veterans affairs committees.

Reagan's announcement was made within an hour after the House Committee on Government Operations approved a bill to establish such a department. Chairman Jack Brooks (D-Tex.) said the agency is needed "to assure that the veterans' needs get the president's personal attention."

Sen. Strom Thurmond (R-S.C.), who was at the meeting, has introduced identical legislation with 30 cosponsors. After the announcement, Thurmond called Reagan "the greatest president since George Washington."

Reagan, who failed in his efforts to eliminate the Education and Energy departments early in his administration, said "Yes," when asked if the move for a new department would be supported in Congress.

"This is a personal decision that I have thought about for some time," Reagan said. "Veterans have always had a strong voice in our government. It's time to give them the recognition they so rightly deserve."

White House spokesman Marlin Fitzwater, asked how Reagan's endorsement fit his previous complaints about government, said making the VA a department "would not necessarily increase its size or budget but would give it a greater say in the councils of government and would make it an active and working part of the president's Cabinet."

Under the Reagan administration, some veterans have been required for the first time to pay a portion of the costs of their treatment at VA hospitals.

"Some feel the VA is run now by the Office of Management and Budget," said House Veterans' Affairs Committee Chairman G.V. (Sonny) Montgomery (D-Miss.). "Veterans programs are too important to be left to mid-level decision-makers at OMB."

The VA, which has an extensive health care system, has more than 240,000 employes and an annual budget approaching $28 billion. If Congress agrees, it would become the second-largest federal department in employment, behind the Defense Department.