It's thought the US President will warn Johnson not to let Brexit put the Good Friday Agreement at risk.
The UK Prime Minister has said he is "not going to disagree with his US counterpart on anything" ahead of the G7 summit in Cornwall.
He was responding to the US President's joke that they both married "way above their station".
Talks between the two leaders may be overshadowed by discussions between the UK and the EU about the Northern Ireland Protocol.
It's thought the US President will warn Johnson not to let Brexit put the Good Friday Agreement at risk.
Top EU official Maros Sefcovic has said the UK must start checking goods entering Northern Ireland, as agreed in the 2019 Brexit "divorce" settlement.
But the UK says it is ready to ignore the rules to prevent further disruption - sparking threats of EU retaliation.