A group of 79 prominent national security names and officials have commended President Obama for using “diplomacy in an effort to reach agreements with Iran” over its nuclear weapons program.

In a letter signed on Thursday, a bipartisan collection of figures praised the Obama administration for seeking to work with Iran’s President Hassan Rouhani, especially as Tehran signals its openness for a diplomatic resolution. The signees include Council on Foreign Relations President Emeritus Les Gelb, along with former Ambassadors Thomas Pickering, Morton Abramowitz and Ryan Crocker.

“The hard work of diplomacy begins now,” the group writes. “Decades of distrust and lack of contact between the two countries will complicate the task of reaching agreements that will provide us the assurance we require that Iran’s nuclear program will be used only for peaceful purposes.”

The group said that the administration would likely “face opposition to [its] decision to engage Iran” but supported the policy nonetheless. The letter was published on the website of The Iran Project, an organization that seeks to “improve official contacts between the United States and Iranian Governments.”

The letter comes as the latest round of the P5+1 talks began on Thursday, with early reports from Geneva indicating some progress on the issue, CNN reports.

Though the letter was signed by a broad array of personalities within the national security community, Washington does not stand entirely united behind the strategy. Sen. Bob Corker, R-Tenn., was planning to block any easement of sanctions on Iran, The Daily Beast reported on Thursday.