LONDON — Britain’s interior minister will use a visit to Silicon Valley on Tuesday to ask Facebook, Microsoft, Twitter, and YouTube to step up efforts to counter or remove content that incites militants. After four militant attacks in Britain that killed 36 people this year, senior ministers have repeatedly demanded that internet companies do more to suppress extremist content and allow access to encrypted communications. In the face of resistance from the industry, Prime Minister Theresa May — a former interior minister — proposed trying to regulate cyberspace after a deadly attack on London Bridge in June. Home Secretary Amber Rudd will meet executives of social media and internet service providers in San Francisco at the Global Internet Forum to Counter Terrorism, whose partners are Facebook, Alphabet, Inc.’s Google, Microsoft and Twitter. The forum was set up to coordinate the companies’ efforts on removing militant content. “Terrorists and extremists have sought to misuse your platforms… This Forum is a crucial way to start turning the tide,” Mr. Rudd will say, according to a statement from the interior ministry.” — Reuters