LONDON (Reuters) - Britain and France will join forces to press companies to do more to tackle online extremism, Prime Minister Theresa May will say on Tuesday, her first foreign trip since her Conservative Party lost its majority in a parliamentary election.

Britain's Prime Minister Theresa May leaves Downing Street in London, June 12, 2017. REUTERS/Hannak McKay

After winning support from the Conservatives to stay on as prime minister after Thursday’s election, May heads to France, wanting to repair her authority and possibly to bask in the popularity of Emmanuel Macron, who last month swept to victory in a presidential contest.

May will also want to raise Britain’s talks to leave the European Union, which have been put in doubt since her governing Conservative Party suffered the setback in the election and now needs to strike a deal with a small Northern Irish party.

But her spokesman said the two leaders will focus on counter-terrorism, and return to May’s election campaign pledge to tackle online extremism following two attacks in as many weeks in Manchester and London that killed 30 people.

“The counter-terrorism cooperation between British and French intelligence agencies is already strong, but President Macron and I agree that more should be done to tackle the terrorist threat online,” May will say, according to her office.

She will add that the measures to “encourage corporations to do more and abide by their social responsibility” could include “creating a new legal liability for tech companies if they fail to remove unacceptable content”.

It was not clear how much further their talks would build on discussions at a meeting of the G7 most industrialized nations last month, where the leaders agreed to do more to purge extremist content.

Internet firms, such as Google and Twitter, say they are investing heavily and employing thousands of people to take down hate speech and violent content on their platforms, with evidence their efforts are working.

But the companies say they also struggle to identify replacement accounts that quickly reappear.

After two Islamist attacks in less than two weeks, May’s bid to clamp down on internet extremism has struck a chord with international leaders especially Macron, whose country has suffered several jihadist attacks since 2015.

“(At the G7) they had a very good conversation on how they could work together in order to make social media companies do more to address the fact their platforms are used to spread extremism,” May’s spokesman said.

“I would expect that conversation to continue tomorrow.”