WASHINGTON, March 16--President Eisenhower announced today a conditional willingness to attend a summit conference with the Soviet Union.

But he also said the United States and its Allies "stand firm wherever the probing finger of an aggressor may point."

The chief executive reported to the nation by radio and television on the Berlin crisis. He took the expected stand that the United States is not abandoning any rights or deserting a free people but still is ready to negotiate differences.

In unmistakable terms, Eisenhower lot the American people, the Soviet Union and the world know that the United States has no intention to "try to purchase peace by forsaking two million free people of Berlin."

The President spoke of the possibility the Berlin situation might carry the seeds of war. But he said "the risk of war is minimized if we stand firm."

Herter Defends Foreign Aid Program

WASHINGTON, March 16--Any slash in President Eisenhower's $3,930,000,000 foreign aid program would show "we are weakening in our determination" to oppose mounting Communist pressures, Acting Secretary of State Christian A. Herter said today.

"If it were not for this program," Herter told the House Foreign Affairs Committee, "we would be seeing large portions of the world in Communist hands as of this moment."

Herter, standing in for the ailing Secretary of State John Foster Dulles, opened the administration's drive to head off fund-cutting proposals by critics of the aid program.

One big reason for leaving the administration program intact, Herter said, is the five-year-old campaign by the Soviet Union and its Chinese Communist allies to outdo the United States in helping underdeveloped countries.