Group of Seven leaders started a two-day meeting Friday in Taormina, Sicily, focusing on ways to address pressing global issues such as terrorism, climate change, trade and North Korea's nuclear and missile programs.

In U.S. President Donald Trump's debut at a G-7 summit, the leaders are expected to have a "robust discussion" on Trump's advocacy for "free, open and fair" trade and Washington's possible departure from the Paris Climate Agreement, according to a senior White House official.

Trump's "America First" policy has fueled concerns in some circles that possible protectionist measures could undermine otherwise solid growth in the world economy.

The leaders of Britain, Canada, France, Germany, Japan, Italy and the United States met after a suicide bombing Monday in Britain killed more than 20 people and North Korea launched another ballistic missile Sunday, moving closer to developing an intercontinental ballistic missile that could strike the U.S. mainland.

Along with Trump, French President Emmanuel Macron, British Prime Minister Theresa May and Italian Prime Minister Paolo Gentiloni joined a G-7 summit for the first time.

Speaking to reporters Thursday, Gary Cohn, director of the White House National Economic Council, said May and Trump will have a lot to say about terrorism and terrorist financing, given Monday's deadly attack in Manchester and Trump's earlier trip to the Middle East where he pledged to defeat the Islamic State terrorist group operating in Iraq and Syria.

Japanese Prime Minister Shinzo Abe said separately that the G-7 "will show our resolve to fight against terrorist attacks."

Cohn said Trump will explain his position on trade. "What the president means by free and open is, we will treat you the way you treat us, meaning if you don't have barriers to trade or you don't have tariffs, we won't have tariffs."

Trump's objective is "not to create tariffs in the United States" but to "level the playing field" for American businesses with foreign competitors, he said.

Cohn also said Trump, who once dismissed global warming as a hoax, is interested to hear what his G-7 peers have to say about climate issues because he will make a decision after the summit as to whether the United States will walk away from its commitments to cut greenhouse gas emissions under the 2015 pact.

The levels that were agreed to by the administration of Trump's predecessor Barack Obama would be "highly crippling" to U.S. economic growth, according to the White House official.

Referring to North Korea, Abe said Thursday that the G-7 leaders "will be united to address" the North Korean nuclear issue as it poses "a serious threat to the world."

A Japanese Foreign Ministry official said Tokyo believes European leaders will share the view with Japan, the United States and South Korea that North Korea's repeated nuclear tests and ballistic missile launches are "not only a regional issue but a global issue."

Among other topics, the G-7 leaders are expected to discuss Ukraine, maritime security, and food security, as well as immigration and refugees.

On Saturday, the G-7 will hold an outreach session focusing on innovation and development in Africa with leaders from Ethiopia, Kenya, Niger, Nigeria and Tunisia, as well as the heads of international organizations.