The three nations said in a joint statement that the agreement is an "affirmation of the respect for the sovereignty of states and non-interference in internal affairs."
"The U.S. encourages war while China pushes the opposite."
Iran and Saudi Arabia "also expressed their appreciation and gratitude to the leadership and government of the People's Republic of China for hosting and sponsoring the talks, and the efforts it placed towards its success," the statement said.
United Nations spokesperson Stéphane Dujarric thanked China for its role in the deal, asserting in a statement that "good neighborly relations between Iran and Saudi Arabia are essential for the stability of the Gulf region."
Amy Hawthorne, deputy director for research at the Project on Middle East Democracy, a Washington, D.C.-based nonprofit group, toldThe New York Times that "China's prestigious accomplishment vaults it into a new league diplomatically and outshines anything the U.S. has been able to achieve in the region since [President Joe] Biden came to office."
Yun Sun, director of the China program at the Stimson Center, a think tank in Washington, D.C., called the deal a sign of "a battle of narratives for the future of the international order."
CNN's Tamara Qiblawi called the agreement "the start of a new era, with China front and center."
Meanwhile, Ahmed Aboudouh, a nonresident fellow at the Atlantic Council, another D.C. think tank, wrote that "China just left the U.S. with a bloody nose in the Gulf."
At the Carnegie Endowment, yet another think tank located in the nation's capital, senior fellow Aaron David Miller tweeted that the deal "boosts Beijing and legitimizes Tehran. It's a middle finger to Biden and a practical calculation of Saudi interests"
Some observers compared U.S. and Chinese policies and actions in the Middle East.
"The U.S. is supporting one side and suppressing the other, while China is trying to make both parties move closer," Wu Xinbo, dean of international studies at Fudan University in Shanghai, told the Times. "It is a different diplomatic paradigm."
Murtaza Hussein, a reporter for The Intercept,tweeted that the fact that the agreement "was mediated by China as a trusted outside party shows shortcomings of belligerent U.S. approach to the region."
While cautiously welcoming the agreement, Biden administration officials expressed skepticism that Iran would live up to its end of the bargain.
"This is not a regime that typically does honor its word, so we hope that they do," White House National Security Council Strategic Coordinator John Kirby told reporters on Friday—apparently without any sense of irony over the fact that the United States unilaterally abrogated the Iran nuclear deal during the Trump administration.
Kirby added that the Biden administration would "like to see this war in Yemen end," but he did not acknowledge U.S. support for the Saudi-led intervention in a civil war that's directly or indirectly killed nearly 400,000 people since 2014, according to United Nations humanitarian officials.
U.S relations with Saudi Arabia have been strained during the tenure of President Joe Biden. While Biden—who once vowed to make the repressive kingdom a "pariah" over the gruesome murder of journalist Jamal Khashoggi—has been willing to tolerate Saudi human rights abuses and war crimes, the president has expressed anger and frustration over the monarchy's decision to reduce oil production amid soaring U.S. gasoline prices and Russia's invasion of Ukraine.
Nevertheless, the Biden administration is currently trying to broker a peace deal between Saudi Arabia and Israel following the Trump administration's mediation of the Abraham Accords, a series of diplomatic normalization agreements between Israel and erstwhile enemies the United Arab Emirates and Bahrain.
The United States, which played a key role in overthrowing Iran's progressive government in a 1953 coup, has not had diplomatic relations with Tehran since shortly after the current Islamist regime overthrew the U.S.-backed monarchy that ruled with a brutal hand for 25 years following the coup.
Jonathan Panikoff, director of the Scowcroft Middle East Security Initiative in the Middle East Programs for the Atlantic Council, urged the U.S. to maintain friendly relations with brutal dictatorships in the region in order to prevent Chinese hegemony there.
Panikoff wrote in an Atlantic Council analysis:
We may now be seeing the emergence of China's political role in the region and it should be a warning to U.S. policymakers: Leave the Middle East and abandon ties with sometimes frustrating, even barbarous, but long-standing allies, and you'll simply be leaving a vacuum for China to fill. And make no mistake, a China-dominated Middle East would fundamentally undermine U.S. commercial, energy, and national security.
Other observers also worried about China's rising power in the Middle East and beyond.
New York Times China correspondent David Pierson wrote Saturday that China's role in the Iran-Saudi Arabia rapprochement shows Chinese President Xi Jinping's "ambition of offering an alternative to a U.S.-led world order."
According to Pierson:
The vision Mr. Xi has laid out is one that wrests power from Washington in favor of multilateralism and so-called noninterference, a word that China uses to argue that nations should not meddle in each other's internal affairs, by criticizing human rights abuses, for example.
The Saudi-Iran agreement reflects this vision. China's engagement in the region has for years been rooted in delivering mutual economic benefits and shunning Western ideals of liberalism that have complicated Washington’s ability to expand its presence in the Gulf.
Pierson noted Xi's Global Security Initiative, which seeks to promote "peaceful coexistence" in a multipolar world that eschews "unilateralism, bloc confrontation, and hegemonism" like U.S. invasions and the North Atlantic Treaty Organization.
"Some analysts say the initiative is essentially a bid to advance Chinese interests by displacing Washington as the world's policeman," wrote Pierson. "The plan calls for respect of countries' 'indivisible security,' a Soviet term used to argue against U.S.-led alliances on China's periphery."
The U.S. has attacked, invaded, or occupied more than 20 countries since 1950. During that same period, China has invaded two countries—India and Vietnam.
"The Chinese, who for years played only a secondary role in the region, have suddenly transformed themselves into the new power player."
New York Times chief White House correspondent Peter Baker also published an article Saturday about how the "China-brokered deal upends Mideast diplomacy and challenges [the] U.S."
"The Americans, who have been the central actors in the Middle East for the past three-quarters of a century, almost always the ones in the room where it happened, now find themselves on the sidelines during a moment of significant change," fretted Baker. "The Chinese, who for years played only a secondary role in the region, have suddenly transformed themselves into the new power player."
Some experts asserted that more peace in the Middle East would be a good thing, no matter who brokers it.
"While many in Washington will view China's emerging role as mediator in the Middle East as a threat, the reality is that a more stable Middle East where the Iranians and Saudis aren't at each other's throats also benefits the United States," tweeted Trita Parsi, executive vice president of the Washington, D.C.-based Quincy Institute for Responsible Statecraft.
"Unfortunately, the U.S. has adopted an approach to the region that has disabled it from becoming a credible mediator," he lamented. "Too often, Washington takes sides in conflicts and becomes a co-belligerent—as in Yemen—which then reduces its ability to play the role of peacemaker."
"Washington should avoid a scenario where regional players view America as an entrenched warmaker and China as a flexible peacemaker," Parsi cautioned.