US President Donald Trump's envoy to Ukraine on Thursday said the informal security grouping of Iran, Russia, North Korea and China presented a challenge to global security which had not existed in his first term.
"This is a brand new arrangement ... we were not confronted with this four years ago," Keith Kellogg told the Brookings Institution thinktank in Washington DC. "This is not just a European problem. This is a global problem."
"Four years ago," he added, "the North Koreans were over here. The Iranians were over here. The Russians, you know, were over here, working, working (the Ukraine) issue, and then the Chinese were over here. Well, now they're all together," he said.
Russia suggested to the United States that the two powers should hold talks focused on Iran's nuclear program, a Kremlin spokesman said on Wednesday, in yet another sign of converging outlooks on global affairs by Washington and Moscow.
Bloomberg reported on Tuesday that Russia has agreed to assist Washington in communicating with Iran on various issues, including its support for regional groups hostile to the US.
Trump's overtures to Russia have upended international relations in recent weeks and the potential role for Moscow in addressing Tehran disputed nuclear program links the issues more closely.
Iran has provided Russia with hundreds of drones for its full-scale invasion of Ukraine as the two powers heavily sanctioned by the United States have drawn closer.
The potential realignment of Russia and the United States in opposition to Iran's nuclear program might deprive Iran of a key ally - a possibility President Masoud Pezeshkian appeared to acknowledge on Thursday.
"If Russia, the United States, or any other country wants to take action, when our hope is in God and our reliance is on our own beliefs, we will find a way," Pezeshkian said according to a readout of his speech published on the president’s website.
"Today, someone may rebuke us, someone may not cooperate with us, or we may run into conflicts with each other. If we rely on anyone other than God, we will face problems," he added.
Kellogg said Washington's Eurasian adversaries had been disunited previously, adding, "(Trump) kept them all segmented,"
"It's sort of like the game of Whac-A-Mole, that every time a mole would come up, you whack it down. Well, all the moles came up, and now we've got to figure out, okay, how do we do this?"
