Nato's secretary-general, George Robertson, is expected to encourage Switzerland to press ahead with its military reforms, during an official visit to Berne on Thursday.
Robertson will hold talks with the foreign minister, Joseph Deiss, and the defence minister and current president, Adolf Ogi, who is overseeing major reforms of the Swiss army.
He is also expected to thank Switzerland for its contribution to stabilising the Balkans.
The proposed army reforms call for drastic cuts in the number of troops and would allow Swiss soldiers to carry weapons on foreign peace missions.
Robertson implicitly endorsed those plans at a news conference in Brussels on Monday, when he reiterated the alliance's conviction that defence structures must be adapted to the changing nature of security threats.
He said that, with the end of the Cold War, the danger was not so much of a military invasion from a hostile power, but the more dissipated threats of organised crime and refugee movements that stem from poverty and instability.
Nato's secretary-general said armies had to become more mobile if they were to cope with these threats. "If you don't go to the crisis," he warned, "the crisis will come to you."
He said Switzerland knew this from the experience of last year's Kosovo crisis, when tens of thousands of refugees sought refuge from the conflict on Swiss soil.
Ahead of his visit, Robertson also praised Switzerland for participating in Nato's Partnership for Peace (PfP) programme, designed to encourage non-Nato members in Europe to participate in some of its activities.
Switzerland joined the PfP in December 1996 and has a contingent of unarmed troops operating in the Nato-led force in Kosovo. However, the government says there is no question of Switzerland abandoning its neutrality and actually joining the alliance.
Robertson is expected to formally thank Switzerland for its engagement in the Balkans, when he meets the foreign and defence ministers in Berne.
During his visit, he will also address a symposium on security policy, and meet the heads of several Swiss parliamentary committees.
Robertson's visit comes just ahead of the first military exercise to be held in Switzerland under the PfP. From November 5-10, 450 officers from 20 Nato and PfP countries will undergo training in peace support operations.
by Malcolm Shearmur