The United States recovered thousands of old chemical weapons in Iraq from 2004 to 2009 and destroyed almost all of them in secret and via open-air detonation, according to a written summary of its activities prepared by the Organization for the Prohibition of Chemical Weapons, the international body that monitors implementation of the global chemical weapons treaty.

The 30-page summary, prepared after quietly held meetings between the organization’s technical staff and American officials in Washington in 2009, was provided to The New York Times by the Pentagon on Friday.

It included a table disclosing limited details on 95 separate recoveries and destructions of chemical warheads, shells or aviation bombs, for a total of 4,530 munitions from May 2004 through February 2009 — a period of often intense fighting in Iraq.

The United States later recovered more Iraqi chemical weapons, pushing its tally to 4,996 by early 2011, according to redacted intelligence documents obtained by The Times via the Freedom of Information Act.