The European Commissioner for Energy and Climate, Miguel Arias Canete, delivered the message during a visit to Tehran and also said the 28-nation EU, once the biggest importer of Iranian oil, hoped to boost trade with Iran.
"The US withdrawal ... is a violation of morals, the correct way to carry out politics and diplomacy and against international regulations," Rouhani during a meeting with visiting Sri Lanka President Maithripala Sirisena.
Europe's heavyweight economies took steps on Friday to safeguard their interests in Iran, seeking to keep the nuclear deal with Tehran alive after Washington pulled out and said sanctions would follow.
Vladimir Putin, in power since 2000, wants Russia to reduce its dependence on imported goods and technology, a drive that has gathered pace since Russia was hit by Western sanctions.
The Iranian oil industry will continue to develop even if the United States pulls out of the 2015 Iran nuclear deal, and Tehran would see the accord as operational as long as it can sell oil, the Oil Ministry website quoted senior officials as saying.
The US ambassador to the United Nations, Nikki Haley, said on Sunday that the United States is preparing new sanctions on Russia over its support of Syrian President Bashar al-Assad.
Australia's David Warner has joined former captain Steve Smith and batsman Cameron Bancroft in accepting sanctions imposed on him by his cricket board for his role in last month's ball-tampering scandal in South Africa.
North Korea on Sunday slammed the latest US measures against it as an ‘act of war’, after US President Donald Trump announced the ‘heaviest sanctions ever’ on the nuclear-armed regime.
US President Donald Trump has rolled out fresh sanctions against North Korea-linked shipping assets, hailing the package as the ‘heaviest sanctions ever’ levied on the Pyongyang regime.