Topics for the talks, to end Thursday, included legal, financial and environmental aspects of the proposed radar base project.
The Czech government delegation was being headed by Ivan Dvorak, chief of the strategic defense planning department of the Foreign Ministry. The United States was represented by a delegation headed by U.S. State Department special envoy Jackson Mc Donald.
The U.S. made a formal request in January to place a radar base near Prague, as part of a defense shield that Washington says is needed to protect European allies against a potential threat from Iran.
The U.S. also wants to place 10 interceptor missiles in neighboring Poland as part of the system. The two former Soviet satellites are now NATO members.
If a deal with the U.S. is reached, the plan would go before the Czech Parliament for a vote, but no decision is expected this year.