"For the past two years, the US government has used its economic, financial and military power through an aggressive approach to disrupt all international structures and regulations," Rouhani said today in Kyrgyz capital city of Bishkek, addressing a meeting of the Shanghai Cooperation Organization - a Eurasian security alliance that includes China, India and Russia.
This has turned the US administration "into a serious threat for the stability of the region and the world", he noted.
"The Islamic Republic of Iran believes that today, the international community has been challenged more than ever by the issue of unilateralism, and the problems and complexities of today's world, especially terrorism, extremism and drug trafficking, have made multilateralism a necessity," Rouhani added.
Rouhani also warned that "terrorism, in its different forms, extremism, unilateralism and interference of extra-regional countries in the affairs of other regions and interference in the internal affairs of other countries have put the international community in a grave situation."
The situation, he noted, can pose a threat to the stability, security and interests of all countries around the world.
"Today, we all have to be united from the East to the West against the danger of extremism; because extremism threatens development, peace and security of the world," Rouhani said.
"It does not matter whether we are Muslim, Christian, Jewish, Buddhist or following any other religion; what matters is to be united against extremism of any color, race or religion."
On Thursday and speaking at Tehran's Mehrabad International Airport before leaving on a two-leg trip to Kyrgyzstan and Tajikistan, Rouhani said security of the entire world, specially the Persian Gulf region, is of high significance to Iran.
The remarks came following attacks on two tankers in the Sea of Oman near the Strait of Hormuz.
"Today, whether in the Persian Gulf region, the Middle East or the entire world, the issue of security bears special and unique significance for us," Rouhani asserted.
Iran, he added, has always dedicated its efforts to guarding regional peace and security, adding that the Islamic Republic has practically shown over the past years how much it is sensitive about the security of its neighboring and regional countries.
Citing more proof of Iran's dedication to preservation of regional and international security, Rouhani reminded how the International Atomic Energy Agency has, in 15 successive reports, verified the country's compliance with its commitments under the 2015 deal with six world powers, known as the Joint Comprehensive Plan of Action (JCPOA).
"Unfortunately, however, the United States trampled on this agreement, violated UN Security Council Resolution 2231 and launched economic war and terrorism" against the Islamic Republic, the president stated.
The US left the deal, which has the UK, France, Russia, China, and Germany as its other signatories, last May, although, the agreement has been ratified in the form of the UNSC resolution. It then restored the sanctions that had been lifted by the accord.
Rouhani said, "What the US is doing to the JCPOA today is beyond violating the [UN Security Council] resolution or contravening a contract."
"This is, in fact, economic terrorism," Iran's president said, adding, "The US has, for the first time, openly launched war on a nation, especially the [Iranian] society's vulnerable classes."
Rouhani said by imposing sanctions, the US has launched a war against "millions of culturally-aware and understanding people, notably those from the weak classes." Nevertheless, "our country will surely be the victor," Rouhani noted.
He said he was making the visit to Kyrgyzstan at the invitation of the country's president in order to attend the SCO summit, which would focus on the security situation and other matters surrounding the region.
Terrorism forms a focal point of discussion during the upcoming summit, the president said, adding, "From our vantage point, terrorism is condemned in all its aspects."
Rouhani said that in addition to delivering a speech at the SCO conference, he was looking forward to holding talks with the leaders of Russia and China as well as that of the host country.
Iran's president also said that he would participate in the Fifth Summit of Heads of State of the Conference on Interaction and Confidence Building Measures in Asia (CICA) in Tajikistan, where he would also hold meetings with participating leaders.