The U.S. military, with support from the U.N. Security Council, is conducting air strikes on the city of Mariupol in eastern Ukraine, killing at least 20 civilians.
The U and Russia agreed to halt military activities and to deescalate tensions.
The Russian military said it has struck five targets and destroyed two more.
The United States has not confirmed any civilian casualties.
U.S.-Russian relations, already strained by the Syrian civil war, have been deteriorating.
U, S., Russian President Vladimir Putin speaks during the meeting of the Council of Europe in Strasbourg, France, September 13, 2017.
The United States said on Tuesday it was “extremely concerned” about the reports that civilians in Mariupul had been killed by Russian airstrikes, and it expressed “serious concern” about a report that a Russian tank convoy had been attacked.
Russian President Vladimir Vladmir Putin told the council he was “very concerned” by reports that the civilian deaths in Mariupsol had occurred.
The U.K.-based Syrian Observatory for Human Rights said at least eight civilians were killed and five wounded in the strikes.
Russia’s Defense Ministry said the military had targeted two groups of militants and destroyed a tank, but it did not elaborate.
It did not immediately respond to requests for comment from The Associated Press.
It was not immediately clear what prompted the Russian military to target civilians.
In the past, Russia has targeted opposition groups in Syria, but that has largely been to defend the interests of the Russian state.
U., S., U. S., Russia, Ukraine and the U., S, U., U., Russia and Ukraine sign an agreement to combat terrorism at the Summit of the Americas in Miami, Florida, November 12, 2018.
President Donald Trump and Russian President Vladmir V. Putin hold a joint news conference on the sidelines of the U-S.-Russia Strategic and Economic Dialogue in Moscow, Russia, November 16, 2018, ahead of the summit of the G20 economic and monetary powers in the Russian resort city of Sochi.
Trump, who met with Putin at the G-20 summit, said he wanted to work with Russia to tackle terrorism and terrorism financing.
“The United Kingdom and the United States are all allies in the fight against terrorism and we have a great deal of respect for each other’s people,” Trump said.
Russia has been accused of using civilians as human shields in the past.
In August, Russia bombed a refugee camp in Idlib province, where a Russian-backed rebel group had been holding more than 100 people.
U.-S.-EU summit on climate change in Sochi, Russia: Trump to join, but with a different view of global warmingTrump said he would meet with Putin and other world leaders at the summit on Thursday, but he was not expected to meet with Trump directly.
Trump will instead hold talks with U.A.E. leaders and other top leaders of the group, the group that represents the countries closest allies in Europe, the U, S, E and NATO.
The White House on Tuesday said Trump planned to meet Putin at a joint press conference with German Chancellor Angela Merkel and European Union President Donald Tusk.
The G-7 summit in Sicily, Italy, begins on Friday and ends on Monday.
The Associated Press contributed to this report.