Addressing journalists, the Prime Minister spoke of the meeting she had with G7 delegates about the UK’s divorce from the EU and its plans for trade after Brexit.
Mrs May said she was committed to “free trade and open markets” before bashing “globalisation”.
She said: “As we prepare to leave the European Union, I reiterated the UK’s abiding commitment to free trade and open markets.
“But I and my fellow world leaders also recognised that some people feel left behind by globalisation and that not all countries are playing by the rules.
Theresa May spoke of the "level playing field for trade" presented by WTO rules
I and my fellow world leaders also recognised that some people feel left behind by globalisation and that not all countries are playing by the rules
“We need to show our citizens that the global economy can truly work for everyone. This means recognising the importance of the international rules-based system and the World Trade Organisation in creating a level playing field for trade but excepting that we need to make the system work better.
“And it means taking action to ensure all our citizens can share in the benefits of globalisation and support those who feel they have lost out.”
The Tory leader also lashed out at Jeremy Corbyn as she said there can never be an excuse for terrorism in a scathing attack following the G7 summit.
The Prime Minister hit out at the Labour leader, as she said she had been in Italy with other G7 leaders "working to fight terrorism" while Mr Corbyn "said that terror attacks in Britain are our own fault".
G7 summit 2017 in pictures
Fri, May 26, 2017
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Donald Trump will face Theresa May and world leaders at the G7 summit in Sicily
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G7 Summit in Taormina
Theresa May also blasted Jeremy Corbyn over his speech on foreign policy
She said: “Jeremy Corbyn has said that terror attacks in Britain are our own fault and he’s chosen to do that just a few days after one of the worst atrocities we have experienced in the United Kingdom.
"I want to make it clear: there can never ever be an excuse for terrorism.”
The comments come after Mr Corbyn outlined his party’s vision for foreign policy in the UK.
He said “many experts” had linked Britain’s involvement in wars around the world to terrorism in the UK.