Prime Minister Justin Trudeau is condemning Iran's missile attack on Israel, but says the international community must do everything it can to help avoid a bigger regional war.

Exchanges of fire between Israel and Hezbollah in Lebanon over the last year erupted into broader violence in the last week as Israel ramped up its campaign against Hezbollah by air and Tuesday began sending in ground troops.

Also on Tuesday, Iran launched some 200 ballistic missiles at Israel, and warned of a "harsher" attack if Israel responds in kind.

Trudeau called Iran's attack a further destabilizing action by a "terrorist regime" that put civilians at risk and runs the risk of a wider war.

He says he spoke to other G7 leaders in an early morning call and all agreed the international community must do everything it can to achieve peace and stability in the region.

Earlier in the day, UN Secretary-General Antonio Guterres told an emergency meeting of the UN Security Council that in just a week the alarming situation in Lebanon has gone from bad "to much, much worse," and called for an end to the hostilities.