http://www.state.gov/t/ac/rls/fs/2004/33147.htmis the framework but China hasn't signed on yet.
Origin and Purpose
The Treaty on Open Skies entered into force on January 1, 2002, and currently has 30 States Parties. The Treaty establishes a regime of unarmed aerial observation flights over the entire territory of its participants. The Treaty is designed to enhance mutual understanding and confidence by giving all participants, regardless of size, a direct role in gathering information about military forces and activities of concern to them. Open Skies is one of the most wide-ranging international efforts to date to promote openness and transparency of military forces and activities. The original concept of mutual aerial observation was proposed by President Eisenhower in 1955; the Treaty itself was an initiative of President George H.W. Bush in 1989. The Treaty was negotiated by the then-members of NATO and the Warsaw Pact, and was signed in Helsinki, Finland, on March 24, 1992. The United States ratified it in 1993. This Treaty is not related to civil-aviation open skies agreements.
Membership
The 30 States Parties to the Open Skies Treaty are: Belarus, Belgium, Bosnia-Herzegovina, Bulgaria, Canada, Czech Republic, Denmark, Finland, France, Georgia, Germany, Greece, Hungary, Iceland, Italy, Latvia, Luxembourg, Netherlands, Norway, Poland, Portugal, Romania, Russian Federation, Slovak Republic, Spain, Sweden, Turkey, United Kingdom, Ukraine, and United States. Kyrgyzstan has signed but not yet ratified. The Treaty depositaries are Canada and Hungary.
The Treaty is of unlimited duration and open to accession by other States. States of the former Soviet Union that have not already become States Parties to the Treaty may accede to it at any time. Applications from other interested States are subject to a consensus decision by the Open Skies Consultative Commission (OSCC), the Vienna-based organization charged with facilitating implementation of the Treaty, to which all States Parties belong. Four states have acceded to the Treaty since entry into force: Finland, Sweden, Latvia, and Bosnia-Herzegovina. The OSCC has also approved applications for accession by Lithuania, Estonia, Slovenia, and Croatia. Croatia ratified the Treaty but has not yet deposited its instrument of ratification. Cyprus�s application for accession is pending before the OSCC.