The German government says Chancellor Merkel and French President Emmanuel Macron have discussed the situation in Iran in a joint telephone call with Russian President Vladimir Putin.
Merkel's office said in a statement Tuesday that the three leaders "underlined the need to persuade Iran to remain in the nuclear agreement, which they agreed to maintain."
Iran's President Hassan Rouhani says the United States will not defeat Iran with economic pressure.
In a live broadcast on state TV, Rouhani says: "The Iranian nation will not be defeated by America, the White House could not defeat the Iranian nation."
Rouhani referred to recently imposed sanctions by the U.S., which have made conditions for Iranians difficult, saying: "But at the end of the road, the victory is ours."
Rouhani called the U.S. a "bully" for its measures against Iran.
Last year, the U.S. withdrew from a nuclear deal between Iran and world powers and re-imposed sanctions on Iran targeting the country's oil sector.
Former U.S. Defense Secretary Jim Mattis says America "needs to engage more in the world and intervene militarily less."
Mattis, a retired Marine general, spoke on Monday night at a previously unannounced speech before a Ramadan lecture series in honor of Abu Dhabi's powerful crown prince, Sheikh Mohammed bin Zayed Al Nahyan.
According to a report in the state-linked newspaper The National, Mattis stressed that "Iran's behavior must change." However, he stressed that unilateral action is not the way forward with Iran and that the "military must work to buy time for diplomats to work their magic."
Speaking about America in general, Mattis said: "America will frustrate you at times because of its form of government, but the UAE and America will always find their way back to common ground, on that I have no doubt."
Iran's president has told a group of clerics that he is seeking expanded, wartime executive powers to better deal with an "economic war" triggered by the Trump administration's pullout from the nuclear deal and escalating U.S. sanctions.
The state IRNA news agency reported late Monday that President Hassan Rouhani cited the 1980s war with Iraq, when a wartime supreme council was able to bypass other branches to make decisions regarding the economy and the war.
The report didn't say what the new powers would entail but quoted Rouhani as saying that "today, we need such powers."
Rouhani says Iran is facing unprecedented problems in "banking and selling oil" but that the country "is united that we should resist the U.S. and the sanctions."
Yemen's Houthi rebels say they launched a bomb-laden drone targeting an airport in Saudi Arabia that also has a military base inside of it.
The Houthi's Al-Masirah satellite news channel said early on Tuesday they targeted the airport in Najran with a Qasef-2K drone, striking an "arms depot" there.
A statement earlier Tuesday on the state-run Saudi Press Agency quoted Saudi-led coalition spokesman Col. Turki al-Maliki as saying the Houthis "had tried to target" a civilian site in Najran.
The New York Times last year reported that American intelligence analysts were based in Najran assisting the Saudis. The Pentagon did not immediately respond to a request for comment.
Last week, the Houthis launched a coordinated drone attack on a Saudi oil pipeline amid heightened tensions between Iran and the U.S.