Johnson will visit a military base to announce new funding for local communities, saying that Britain is a “global brand and together we are safer, stronger and more prosperous”, according to a statement released by his Downing Street Office.
It will be the first stop on a tour of the countries that make up the United Kingdom, as he attempts to win support for his Brexit plans and head off talk of a break-up of the union.
Scottish First Minister Nicola Sturgeon said last week that Scotland, which voted to remain in the EU in the 2016 referendum, needed an “alternative option” to Johnson’s Brexit strategy.
He has promised that Britain will leave the EU on October 31, with or without a deal.
Sturgeon, who leads the separatist Scottish National Party (SNP), told Johnson that the devolved Scottish Parliament would consider legislation in the coming months for another vote on seceding from the United Kingdom.
Irish prime minister Leo Varadkar has also said that a no-deal Brexit would make more people in Northern Ireland “come to question the union” with Britain.
Johnson, who decided that he will take the symbolic title of Minister for the Union alongside that of prime minister, will announce £300 million (£370 million, 332 million euros) of new investment for Scotland, Wales and Northern Ireland during Monday’s visit.
“Important projects like the government’s growth deals… will open up opportunities across our union so people in every corner of the United Kingdom can realize their potential,” he was to say.
“As we prepare for our bright future after Brexit, it’s vital we renew the ties that bind our United Kingdom.
“I look forward to visiting Wales and Northern Ireland to ensure that every decision I make as prime minister promotes and strengthens our union,” he will add.
Johnson plans to visit local farmers in Wales and discuss the ongoing talks to restore the devolved government when he visits Northern Ireland.
The investment boost comes after the prime minister announced a £3.6 billion fund supporting 100 towns in England, raising suggestions that he is already in campaign mode for an election.
Many MPs are opposed to leaving the EU without a deal, and could try and topple the government in an attempt to prevent it, potentially triggering a vote.
Johnson has made a busy start to his premiership as he attempts win over public opinion for his Brexit plans and put pressure on those who could bring him down.
But the EU has already said his demands to renegotiate the deal struck by his predecessor Theresa May, but which was three times rejected by parliament, are “unacceptable.”