Fielding questions from European television reporters, President Carter defended his economic and energy policies yesterday and said he hoped the American people learned from the Vietnam war the danger of military intervention in distant lands not vital to U.S. security.

In a possible preview of the attitudes he could encounter at a summit meeting later this week in London, the President was asked whether the United States' industrial allies have a right to feel "let down" by the "caution and conservatism" of his economic policies.

He also was asked whether his energy proposals weren't "strong on rhetoric and preaching and rather light when it actually comes to the measures."

In both cases, Carter defended administration policies. Even without the $50-per-person tax rebate plan that he abandoned, he said, the administration's remaining economic stimulus package will be "adequate" to spur sufficient growth in the U.S. economy. He also described his energy plan as "adequate" and said the conservation goals he has set for the country are "very stringent."

The President will leave Washington Thursday for London, where he is to attend a two-day summit conference, which will be dominated by economic issues, with the leaders of West Germany, France, Great Britain, Italy, Japan and Canada.

During the six-day trip he also will fly to Geneva to meet President Hafez Assad of Syria, and will attend a meeting of the North Atlantic Treaty Organization in London.

Carter's interview yesterday with British, French and West German television correspondents was designed to provide Europeans with an advance look at the new American President.

In answer to other questions, Carter said the United States is committed to supplying nuclear fuels for power plants to other nations and to preventing nonnuclear nations from developing atomic weapons.

"I don't think these two thrusts of our policy are incompatible," he said.

The President reaffirmed his commitment to human rights around the world, describing it as a commitment he intends to keep "until the last day I am in office."

Asked about the willingness of Americans to intervene militarily in foreign countries, Carter said:

"I think the unfortunate experience that we had in Vietnam has impressed on the American people deeply, and I hope permanently, the danger of our country resorting to military means in a distant place on earth when our own security is not being threatened . . . "

He said exceptions to this were Japan and the NATO countries of Western Europe, where the United States has "deep commitments."

Earlier yesterday, the President met with the congressional leadership, Cabinet secretaries and other key administration figures to discuss the government budget process.

Participants said Carter acknowledged that he had made mistakes in dealing with Congress and emphasized that Congress and the White House must cooperate if he is to fulfill his pledge to balance the budget by 1980.