Marco Rubio said there are "some good signs" that a deal to end the Iran war could be in sight - but added that he doesn't "want to be overly optimistic".
International concern has been growing following weeks of nationwide protests in Bolivia - with the country's president saying he will reshuffle his cabinet in response to the unrest.
The UK will provide up to £20m to help contain an Ebola outbreak suspected of killing more than 130 people in the Democratic Republic of the Congo and Uganda.
Israeli police have been filmed forcing activists to kneel on the ground with their hands tied behind their backs while the country's national security minister tells them they should be imprisoned for a long time.
Australia is likely facing its "biggest diphtheria outbreak" in decades, the country's health minister has warned, as an investigation continues into a possible death.