Prime Minister Mark Carney says he's hopeful the ceasefire between Iran and Israel will provide an 'opportunity' to end hostilities in Gaza and bring a broader Middle East peace.

The two-day NATO summit is set to focus on boosting allies' defence spending, but is starting a day after Iran retaliated against U.S. military strikes on its nuclear facilities.

The U.S. and other NATO allies said at Tuesday's summit they will send Ukraine dozens of air defense systems in the coming months, including at least four Patriot systems.

'Two per cent is now the floor for our defence spending,' said NATO Secretary-General Jens Stoltenberg. 'It's not good enough what we do now.'

Analysts say Canada should be front-and-centre for talks on Arctic and Indo-Pacific security, but its failure to meet defence spending targets may get in the way.

Canada will be reassuring allies of its commitment to NATO when the prime minister heads to Washington, D.C., this week for a summit of the alliance's leaders.