The leaders of the Group of Seven industrialized nations on Monday failed to adopt a comprehensive joint declaration of the type customarily issued in decades past, leaving unresolved some globally critical issues at the conclusion of their three-day talks.

The G-7 managed to issue a concise "declaration" summing up their discussions on five topics -- trade, Hong Kong, Iran, Ukraine and Libya -- but the document is a different format compared with what has been released since the late 1970s.

Before the leaders met, French President Emmanuel Macron, this year's G-7 host, indicated a post-summit joint communique would not be issued for the first time in the group's 44-year history to avert an internal conflict.

Macron, however, said at a press conference after the summit that the G-7 successfully endorsed a "one-page declaration," adding, "I can say that what we were really keen on was to convey a positive and joint message following our discussions."

But reflecting a rift between the United States and other G-7 members, Macron said U.S. President Donald Trump skipped Monday's session on climate. Trump, who decided to withdraw Washington from the Paris climate agreement, had been scheduled to attend.

On the final day of their gathering in the French resort town of Biarritz, the G-7 countries exchanged views on the recent unrest in Hong Kong and a series of North Korean test-firings of short-range ballistic missiles.

Many G-7 leaders "expressed concern" over the current situation in Hong Kong, a Japanese government official said, amid growing fears China may use military force to crack down on violent protests there. In the one-page declaration, the G-7 "calls for violence to be avoided."

The leaders from Britain, Canada, France, Germany, Italy, Japan and the United States plus the European Union confirmed they will urge China to "play a constructive role in the international community," the official said, a day after a Hong Kong police officer fired a warning gunshot for the first time in the city's months-long protest movement.

In Hong Kong, large-scale demonstrations have continued in opposition to a controversial extradition bill that could enable the transfer of criminal suspects to mainland China.

The bill, now suspended but not withdrawn, could bolster the influence of communist China and erode liberties in the former British colony, critics say.

Trump has warned China that if it violently intervenes to end the protests, as it did during the military crackdown on the pro-democracy movement at Beijing's Tiananmen Square in 1989, bilateral trade talks would be hampered.

Since July 25, meanwhile, North Korea has carried out seven launches of projectiles believed to be short-range ballistic missiles, in what Japan says is a violation of U.N. Security Council resolutions barring Pyongyang from using ballistic technology.

Japanese Prime Minister Shinzo Abe said at a separate news conference on Monday that the G-7 countries "agreed to work together to achieve denuclearization of the Korean Peninsula."

During the first two days, the G-7 leaders discussed the 2015 Iran nuclear deal, from which the United States withdrew last year, Russia's potential return to the group's framework and an escalating tit-for-tat tariff trade war between Washington and Beijing.

The G-7 members shared the view on Saturday that for the sake of peace and stability in the region, Iran should not possess nuclear weapons, but they differed in their approaches to finding a resolution to the issue.

On Sunday, Iranian Foreign Minister Mohammad Javad Zarif made an unannounced trip to Biarritz at the invitation of his French counterpart. Zarif did not hold talks with U.S. officials.

At the joint press conference following the summit with Trump, the host of the G-7 leaders' gathering next year, Macron said he hopes the U.S. president and his Iranian counterpart Hassan Rouhani will meet "in the next few weeks."

Asked about whether Macron's request sounds realistic, Trump said, "It does," adding, "We can't let them have a nuclear weapon, so I think there's a really good chance we would meet."

Although Trump has pushed for a return of Russia to the G-7 group, other member nations remained opposed due largely to a lack of progress on the issue of Russia's annexation of Crimea, sources familiar with the discussions said.

Russia was dropped from the then Group of Eight after its annexation of the territory from Ukraine in 2014, which sparked an international outcry.

Regarding the trade dispute between the world's two biggest economies, the G-7 agreed Sunday to take "every possible measure" to tackle global economic downside risks, but has yet to elaborate what kind of steps it can implement.

On the matter, the declaration released Monday only said that the G-7 "is committed to open and fair world trade and to the stability of the global economy."

In the previous G-7 summit in Canada last year, Trump abruptly backed off from a joint communique, which sums up the leaders' discussions, at the last minute after engaging in a war of words with the host, Canadian Prime Minister Justin Trudeau, over trade policy.