The U.N. has reported that more than 1,000 people, mainly civilians, have been killed this month in Iraq, more than in any single month in the country since 2008.

The U.N.'s human-rights team in Iraq released a report that claims at least 757 civilians died in Nineveh, Diyala and Salahuddin provinces between June 5 and June 22, according to the BBC. The U.N. report also claims that as many as 318 people were killed in that same time in Baghdad and areas in southern Iraq.

Roughly the same number of people have been injured in fighting and other violence in Iraq during that two-and-a-half-week period as Sunni military groups this month have rolled through the northern part of the country, the U.N. report says.

Victims include the number of confirmed executions committed by the Islamic State of Iraq and the Levant forces and prisoners killed by Iraqi forces, Reuters reports.

"This figure -- which should be viewed very much as a minimum -- includes a number of verified summary executions and extra-judicial killings of civilians, police, and soldiers who were hors combat," said Rupert Colville, U.N. human rights spokesman, said in a news briefing, according to Reuters.

U.S. Secretary of State John Kerry on Monday promised "intense and sustained" U.S. support for Iraq, but said the divided country would only survive if Iraqi leaders took urgent steps to bring it together, Reuters reported.

Kerry also held crisis talks on Tuesday with leaders of Iraq's autonomous Kurdish region, urging them to stand with Baghdad in the face of the Sunni insurgents that threatens to disintegrate the country, according to Reuters.

U.S. President Barack Obama has said he won't be sending U.S. troops into battle, but announced last week that up to 300 U.S. Special Operations troops would be sent to advise Iraqi security forces, according to The Washington Post.

"American combat troops are not going to be fighting in Iraq again," Obama said. "This is something that is going to have to be solved by Iraqis."