President Reagan confronted the volatile issue of US nuclear missiles in Western Europe with something of a two-track approach. On the one hand, he reaffirmed that the United States would not agree to forgo the deployment of Pershing-II missiles in Europe if Soviet SS-20 missiles remained in place. At the same time, he said he remained flexible on arms control. He also said British Prime Minister Margaret Thatcher had ''a sort of veto power'' over any decision he might make to launch British-based US cruise missiles in a conflict with the Soviet Union. Control of the missiles is an issue in the current election campaign in Britain, in which Mrs. Thatcher is under pressure from her Labour Party opposition to press the US for joint control.
Meanwhile, the news from overseas was not encouraging to the Reagan White House. The Danish parliament passed a motion compelling the government to press for an extension of NATO's December deadline for deploying the US missiles.