President Barack Obama has vowed that the US will not "leap before we look" in response to Syria's alleged use of chemical weapons.
At a press conference, as part of a visit to Costa Rica, Obama said he does not foresee a scenario in which he would dispatch US troops to Syria.
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The man, who was in his 30s, has not been identified, while several other people are believed to have suffered serious injuries.
The Olympian was one of several sports stars who opened up to the prince during an event for his mental health charity Heads Together.
There will be sunny spells, with temperatures peaking at 23 Celsius (73F). However, Northern Ireland will experience frequent showers.