US President Donald Trump said on Tuesday that Iran will never have a nuclear weapon under the deal with the Middle East country.

"We have our deal done with Iran. It should be successful. It goes to a second stage, which I think will be easier," Trump told reporters on the sidelines of the G7 summit in France.

Trump also said that Israeli Prime Minister Benjamin Netanyahu must now be "more responsible with respect to Lebanon."

The summit kicked off on Monday in Evian, a town on the shores of Lake Geneva in eastern France. According to the agenda, the three-day summit will focus on a range of issues, including the Ukraine crisis, Middle East tensions, and the development of artificial intelligence.