David Cameron has signed the Lough Erne declaration, which, according to the government, "focuses on private enterprise, which drives growth, reduces poverty, and creates jobs and prosperity for people around the world."
The G8 countries aimed to reduce corporate tax evasion and the document says member countries must work on closing tax loopholes.
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It comes after security was stepped up around the country following the Manchester Arena attack which killed 22 people.
A murderer nicknamed 'Houdini' after escaping the death penalty seven times has been given the lethal injection.
The distress signal sparked a police hunt in the area to find the person or group who made it.