In this Jan 9, 2020, photo, US President Donald Trump speaks on proposed changes to the National Environmental Policy Act, at the White House in Washington. (EVAN VUCCI / AP)

WASHINGTON/TEHRAN — US President Donald Trump tweeted Sunday he does not care if Iran agrees to negotiate with the United States even as Iran's Supreme Leader Ayatollah Ali Khamenei sought wider cooperation among regional states.

In a Twitter post, Trump wrote: "Actually, I couldn’t care less if they (Iran) negotiate. Will be totally up to them but, no nuclear weapons and ‘don’t kill your protesters.’"

National Security Adviser Robert O’Brien told Fox News Sunday the Trump administration’s “maximum pressure campaign” was working, adding “Iran is being choked off, and Iran is going to have no other choice but to come to the table.”

In a Twitter post later on Sunday, Trump cited O’Brien’s interview and wrote: “Actually, I couldn’t care less if they negotiate. Will be totally up to them but, no nuclear weapons and ‘don’t kill your protesters.’” A spokesman for O’Brien did not immediately comment. 

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Iran's Ayatollah Ali Khamenei on Sunday urged more cooperation among regional states during a meeting with the visiting Qatari Emir Sheikh Tamim bin Hamad Al Thani.

The current situation of the region makes regional cooperation and the avoidance of reliance on foreigners a necessity, Khamenei said at the meeting.

Iran has repeatedly announced that it is ready for closer cooperation with the regional states, he said.

Khamenei also called for promoting economic ties between Iran and Qatar. 

On his part, the Qatari emir said "we also agree with your remarks considering the enhancement of cooperation among the regional countries, and believe that comprehensive dialogue should be held among the regional countries."