Czechoslovakia and Bulgaria joined their Warsaw Pact allies Friday in announcing cuts in the size of its armed services and defense spending over the next two years.

Czechoslovakia said it will reduce its armed forces by 12,000 men and re-allocate 20,000 others from combat duty to engineering projects in the civilian sector by the end of 1990, according to a statement carried by the official news agency CTK.In Sofia, the government said it will reduce its armed forces by 10,000 men, 200 tanks, 200 artillery systems, 20 aircraft and five naval units. The 1989 defense budget will be reduced by 12 percent.

"This move is a telling indication of the considerable changes brought about in the international situation over the last few years," said President and Communist Party leader Todor Zhivkov.

The changes in Czechoslovakia, which involve a 15 percent cut in defense spending, will include liquidation of 850 tanks, 165 armored vehicles and 51 combat aircraft, CTK said.

"It has been decided to reduce by 12,000 men the combat units of the Czechoslovak People's Army and at the same time reinforce army building organizations by at least 20,000 men," said a statement.