The Nato secretary-general, Jens Stoltenberg, is to use a major speech in London on Thursday to express hope the alliance will hold together in spite of threats from Donald Trump.

He will acknowledge differences and disagreements between the US and other allies are real. But he will argue that Nato has been able to overcome such problems in the past and can do so again.

The Nato summit in Brussels in July is shaping up as one of the most fraught in the alliance’s history, with Trump openly at odds with Germany and Canada on trade and other issues and warning he will deal with Europeans refusing to increase their share of defence spending.

In advance excerpts of his speech, Stoltenberg will argue that maintaining the transatlantic partnership is in the strategic interest of all Nato members.

“The lesson of history is that we have been able to overcome our differences. Again and again, we unite around our common goal. We stand together. We protect each other.”

Russia has been chipping away at Nato since it annexed Crimea in 2014. It has been blamed for cyberattacks, interventions in European elections and for the nerve agent attack in Salisbury in March this year.

In spite of the splits within Nato, Stoltenberg will claim the US, Canada and Europe have grown stronger in defence.