The Competitive Enterprise Institute filed suit Tuesday against the State Department seeking records of conversations involving Obama administration officials who worked on the Paris international climate change accord.

The free-market think tank said it filed a Freedom of Information Act request, or FOIA, with the State Department on Aug. 31 to obtain correspondence between a pair of former Obama officials and two environmental groups.

CEI, suing in U.S. District Court for the District of Columbia, says it is entitled to injunctive relief that would force the State Department to provide the documents, because the agency has not notified the think tank whether it will comply with the request "within the statutory deadline of 20 working days."

"In the absence of the Trump administration taking the initiative to review the internal record of the disgraceful process of circumventing the Senate and the U.S. Constitution to enter the Paris climate treaty, we will continue seeking to make public all of that record we are able," said CEI fellow Chris Horner.

Specifically, the group wants the communications of Todd Stern, who led the U.S. negotiating team for the Paris Agreement, and Sue Biniaz, who served as the lead climate lawyer for the State Department for more than 25 years.

In its FOIA, CEI asked for emails and text messages between Stern and Biniaz, and two environmental groups, the World Wildlife Fund and the Natural Resources Defense Council.

Stern left the Obama administration in 2016 and previously served under President Bill Clinton, for whom he was the senior White House negotiator for the Kyoto climate change protocol. Biniaz began serving in the legal adviser's office at the State Department in 1984 and was the principal lawyer on climate change negotiations since 1989.

CEI has been the subject of legal complaints itself related to its climate change research. Last year, the attorney general of the U.S. Virgin Islands issued a subpoena of CEI, seeking documents to confirm if the think tank collaborated with Exxon Mobil to play down the impacts of climate change. The attorney general, Claude E. Walker, later revoked the subpoena after CEI claimed he was violating the think tank's free speech rights.

The Paris Agreement is an international accord negotiated in 2015 under which nearly 200 nations pledged voluntary targets to cut greenhouse gas emissions.

President Trump announced in June the U.S. would be withdrawing from the deal, because he said the U.S. committed too much compared with other countries and would suffer economically.

The State Department in August filed a formal notice to the United Nations that it intended to withdraw from the Paris agreement, but said the U.S. is open "re-engaging" if it can negotiate different terms. The U.S. cannot officially withdraw until November 2020.