Khamenei, the highest authority in Iran, reluctantly gave his backing for the Iran nuclear deal and has publicly criticized the USA multiple times for not following through on its promises under the agreement.
The show of unity came following Trump's pullout from the JCPOA, and his announcement that the U.S. would reimpose nuclear sanctions on the Islamic Republic.
He likened some Persian Gulf political leaders to "America's slaves", adding that Iran does not want to be like them.
"I said many times from the first day: Don't trust America", Khamenei said.
"The Islamic Republic is prepared to enhance its friendship and mutual cooperation with Sri Lanka", he was quoted as saying in a report by the Leader's website. Rouhani stressed that Iran will stay in the JCPOA with European Union partners, Russian Federation and China.More news: Reports Abound of Nielsen Threatening to Resign
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In a Sunday meeting with visiting Sri Lankan President Maithripala Sirisena in Tehran, the Leader referred to the historical and cultural ties between Iran and sub-continent states including Sri Lanka and said the current level of relations between the two states is way lower than the existing capacities.
Iranian lawmakers also set the Stars and Stripes ablaze inside the parliament and burnt symbolic copies of the nuclear agreement.
IRGC Commander Major General Mohammad Ali Jafari congratulated the nation on the United States' withdrawal from the deal, stressing that the development would not leave any detrimental impact on Iran's national interests, reported ISNA.
"If you can't get a definite guarantee, then the nuclear deal cannot be continued", he said.
Before that message, Khamenei accused Trump of lying during his announcement. Trump also announced plans to reinstate sanctions against Iran.