A Downing Street spokesperson said:
The Canadian Prime Minister Justin Trudeau called the Prime Minister earlier today to congratulate her following the UK election and to discuss how to strengthen and deepen the bilateral relationship between our two countries even further.
He said his thoughts were with the British people following recent tragic events in London.
They agreed the counter-terrorism cooperation between Canadian and British security and intelligence agencies was very strong and would endure. The Prime Minister expressed her desire to build on the momentum from the G7 Summit to accelerate collective action now to tackle Daesh online - including making sure tech companies play their part.
They also discussed the beginning of Brexit negotiations and the Prime Minister said the UK continued to support the EU-Canada Free Trade Agreement.
Both stressed their continued support for the Paris agreement on climate change.
They looked forward to seeing each other in Hamburg next month for the G20 Summit.