Americans continue to approve President Reagan's general performance in office considerably more than they do his handling of key foreign and domestic policy issues, according to the findings of a new Gallup Poll.

These survey findings suggest that, while the public generally admires Reagan for his personal attributes -- his resilience in recovering from the March 30 assassination attempt, for example -- and his willingness to take a sometimes unpopular leadership role in addressing the economic problems of the nation, many people are either dubious or downright skeptical about the effectiveness of the president's approaches to these problems.

In the latest Gallup Poll, two out of three citizens (68 percent) express confidence in Reagan's overall discharge of his presidential duties. Yet approval of his handling of specific problems ranges from a high of 62 percent, for his efforts to improve our national defense, to a low of 30 percent, for the way he is dealing with the situation in El Salvador.

Between these extremes, the president gets favorable ratings of 58 percent for handling economic conditions, 56 percent for dealing with inflation and 53 percent for his handling of relations with the Soviet Union. Reagan gets less than majority support for his approach to energy problems (44 percent) and for dealing with unemployment (42 percent).

The president's overall popularity rating has increased by 8 percentage points since a survey completed before the March 30 attempt on his life.

One specific increase is a 7-percentage-point improvement in favorable attitudes of the president's handling of the energy situation.

On the other hand, favorable public perceptions of Reagan's handling of our relations with the Soviet Union have shown a marginal decline, from 58 percent approval in March to 53 percent at present, and on the Salvadorian situation, from 36 percent to 30 percent.