Currently, Nato members have committed to spend at least 2 per cent of the value of their economies on defence, with the UK spending 2.3 per cent.
The previous Tory government pledged to raise defence spending to 2.5 per cent of GDP. Labour has said it has the same ambition – but has yet to set out a timeline for achieving the goal.
In a bid to beat his rival Kemi Badenoch to Tory leader, Mr Jenrick has also pledged to introduce a “Great Reform Act” – if he eventually becomes prime minister – which would scrap the Climate Change Act, Equality Act and Human Rights Act.
The 42-year-old, who is currently behind in the polls to Ms Badenoch, the shadow housing secretary, also called for more support for military personnel.
“We face an axis of authoritarian states on the offensive but our brave Armed Forces are depleted and under-equipped,” he said.
He cited low stockpiles of ammunition and a “crumbling” nuclear deterrent as warning lights that things must be improved.
“We need a new covenant with our brave service personnel,” Mr Jenrick said.
“That means paying them more to address the recruitment and retention crisis, settling the pay dispute with the RFA [Royal Fleet Auxiliary] crew immediately, and giving veterans in need priority for council housing.”