The singer said her decision to perform is "not a political statement or a commitment to the politics there."
German Foreign Minister Heiko Maas said Europe must create a new system for financial transactions that excludes the U.S. in order to help Iran.
Russia's top diplomat said U.S. sanctions were not about Syria or Ukraine, but "to promote an absolutely hopeless policy of containing the Russian Federation."
While touring a medical factory, North Korean supreme leader Kim Jong Un "said he cannot but be very concerned about and disappointed by the bad situation."
Iran's Foreign Minister, Mohammad Javad Zarif, is stepping up his efforts to save the nuclear deal.
U.S. sanctions on Turkey have effectively split U.S. policy in the region.
Russia and China have sought to expand their ties in the wake of what they consider an aggressive U.S. foreign policy.
Vladimir Putin is looking for ideas to jump-start the economy and increase spending, but one rumored plan is already costing oligarchs billions.
Despite Khamenei promising that war is not an option, he also said that dialogue with Washington is not on the table.
"The reality is that global economic growth is closely linked to trade, and raising tariffs will inevitably reduce the volume of trade and drive down business confidence," the article argued.
The U.S. has already announced incoming sanctions against sensitive electronic imports and senators want fresh restrictions on Russian finance and investments.
Iran's threat to shut down the Strait of Hormuz is unlikely to be carried out, but it would prompt a spike in oil prices and potential U.S. military intervention.
President Donald Trump has said he wants to achieve "world peace," but his rejection of the Obama-era nuclear deal may only lead to more conflict with Iran.
Prices could reach $90 a barrel.
On Sunday, the Iranian rial reached a record nadir in street trading.
The Russian government hit back on sanctions by taking Western cheese, fruit and foodstuffs, only to bulldozer them at the border.
A bipartisan bill wants to halt the possibility of returning to business as usual with the Kremlin, instead asking for a report on Putin's finances and those of his close associates.
"It's absolutely clear that Russia needs to do more," a State Department official said after a report that Russia has issued 700 new work permits this year.
Two former State Department officials who helped craft the 2015 Iran nuclear deal say allies are increasingly frustrated with U.S. financial dominance—and this may be the final straw.