...country, an opinion poll showed on Tuesday.
The United States wants to station elements of its shield in Poland and the Czech Republic as protection from potential missile attacks by countries such as Iran. But Russia says the project threatens its national security.
Sixty-eight percent opposed hosting a radar station as part of the shield, up from 61 percent two months ago, according to the April 2-9 poll by the CVVM agency among 1,011 Czechs.
Twenty-six percent said they supported the plan, up from 25 percent in the previous poll. The proportion of undecided respondents fell to 6 percent from 14 percent.
The dispute over missile defence has badly strained relations between Moscow and Washington and prompted some officials to draw comparisons with the Cold War.
The United States wants to station 10 interceptor missiles in Poland and radar equipment in the Czech Republic, at a cost of $3.5 billion. The radar should be based in the Brdy military training area southwest of Prague.
The plan has sparked opposition from Czech opposition leftist parties as well as some civic organisations.
The centre-right government has rejected calls for a referendum on the radar, but it faces a tough task pushing the plan through parliament where it controls just 100 of 200 seats.
Some government deputies have said they were uneasy about building the radar unless it is a part of a NATO-wide defence scheme, while some opposition deputies have voiced cautious support for the plan.
The Americans have stepped up efforts to win support for the plan, flying several MPs to a similar station in the Marshall Islands in the Pacific Ocean recently.
Lieutenant-General Henry Obering, head of the U.S. Missile Defense Agency, was in Prague on Monday and discussed the plan with Czech parliamentarians.