Tom Cotton says Iran's leaders 'clearly have the message' from his letter

A week after authoring a controversial letter to Iran on behalf of Senate Republicans attempting to thwart President Obama's nuclear negotiations, Sen. Tom Cotton (R-Arkansas) boasted Tuesday that Iranian leaders "clearly have the message now."

"This president views Congress as an afterthought," Cotton said at a Bloomberg event in Washington, explaining his motivation for the move.

"Iran's leaders clearly have the message now, and I think it was important they got the message."

Cotton, who started his first term just 10 weeks ago, led the effort to gather signatures from 46 other Republican senators on a letter addressed to Iran's leaders. The letter warned that Congress wouldn't recognize any agreement reached between Iran and the Obama administration and suggested a new president could "revoke such an executive agreement with the stroke of a pen."

The freshman senator tweeted the letter last Monday to Iranian leaders including the Ayatollah Khamenei, President Hassan Rouhani, and Iran's foreign minister.

Cotton received a prompt reply from Foreign Minister Javad Zarif via Twitter. Zarif chastised the Senators for the letter, which he called a "propaganda ploy."

The Wall Street Journal described Cotton's communiqué as a "coming-out party" for the freshman Senator, given the publicity it garnered for the 37-year-old Arkansas Republican, but Cotton said Tuesday he "absolutely" stands by the letter.

Two signatories, Sens. John McCain (R-Arizona) and Ron Johnson (R-Wisconsin), have already expressed regret for attaching their names to the letter in haste.

The Obama administration criticized Cotton's attempt to undermine U.S. negotiations with Iran for a nuclear deal.

"I'm embarrassed for them," Obama said of the Republicans who signed the letter.