U.S. Environmental Protection Agency administrator Scott Pruitt speaks during a press briefing about President Donald Trump's decision to withdraw from the Paris Agreement at the White House in Washington D.C., capital of the United States, on June 2, 2017. (Xinhua/Mike Theiler)

BOLOGNA, Italy, June 12 (Xinhua) -- A top United States official abruptly left the Group of Seven (G-7) environmental ministerial talks in Bologna on Sunday, just a few hours after it began.

The unscheduled departure of Scott Pruitt, the head of the U.S.'s Environmental Protection Agency, was the talk of the first day of the two-day event.

There was no formal word on why Pruitt left the talks after participating in only a single negotiating session, posing for a group photo with other delegation heads, and holding one-on-one talks with his counterparts from Germany, Japan, and Britain.

In U.S. media, it was reported that Pruitt was "summoned" by U.S. President Donald Trump.

Pruitt's departure comes just days after Trump announced the U.S. would withdraw from the Paris Agreement, a global pact designed to fight against climate change.

Negotiations continued even after Pruitt left Bologna, with more junior U.S. officials heading the U.S. delegation.

Officials from other countries said they focused on negotiating a strong final statement, which is expected to cover not only climate but also energy policy, government incentives, deforestation, recycling, and financial issues.

The G-7 is made up of Canada, France, Germany, Italy, Japan, Britain and the U.S.

The two-day ministerial meeting also includes ministers from Chile, Ethiopia, the Maldives, and Rwanda as special observers, as well as EU officials. The G7 Bologna talks are to wrap up on Monday.