Iran's Foreign Ministry urged that diplomatic exchanges should remain confidential, Iran International reported on Sunday.
The report comes amid contact between the Islamic Republic and the US over reported efforts to reach a nuclear deal.
"Iran's response to the letter has been prepared and delivered. In this regard, the path of #indirect_negotiations with the United States has been put on the agenda. The diplomatic process continues," Iran's government spokesperson shared on X/Twitter on Sunday.
In early March, US President Donald Trump sent a letter to Supreme Leader Ayatollah Khamenei, offering to begin talks between the two parties.
The letter included a two-month deadline by which a new nuclear deal could be reached, two sources confirmed to The Jerusalem Post.
“President Trump made it clear to Ayatollah Khamenei that he wanted to resolve the dispute over Iran’s nuclear program diplomatically – and very soon – and if this were not possible, there would be other ways to resolve the dispute," NSC Spokesman Brian Hughes told the Post.
Iran's Abbas Araghchi: Donald Trump's letter was deceptive
Khamenei stated the letter was deceptive, while Foreign Minister Abbas Araghchi said the letter was being evaluated.
On Friday, Araghchi was reported by state media as saying that while Trump’s letter contained threats, it also left the door open to diplomacy. He did not elaborate.
On Friday, Araghchi said his country has responded to the letter via Oman.
Amichai Stein and Reuters contributed to this report.