Secretary of State Alexander M. Haig Jr. canceled a scheduled visit to Spain, where he was to hammer out a new defense treaty between the United States and Spain. Officials of both governments gave no specific reasons for the cancellation.
Sources have said the Falkland Islands crisis, in which Spain and the US have conflicting loyalties, has raised the question of how Madrid would react in a similar situation that might involve US operations against a country with which Spain was friendly.
The present treaty, which expires on Friday, was last renewed in 1976, and Spanish officials say any new agreement must take into account Spain's status as a democracy and as a future member of the North Atlantic Treaty Organization and the European Community.
Spain and the US have been linked since 1953 by the Defense and Cooperation Agreement, which gives US forces the use of four bases on Spanish territory in exchange for grants and credits to Spain. Washington has proposed tripling its aid package to about $450 million a year, a move a spokesman for the US embassy in Madrid called ''an indication of our good faith.'' Such aid would be subject to congressional approval.