World leaders struggled Saturday to find common ground in the fight against climate change in the wake of President Trump’s decision to leave the Paris agreement.

The final statement of the Group of 20 summit in Hamburg, Germany, underlined that the other countries and the European Union supported the Paris climate agreement rejected by Trump. They called the deal to reduce greenhouse gases "irreversible" and vowed to implement it quickly and without exception.

German Chancellor Angela Merkel called the United States' position "regrettable." She said the statement also makes clear other summit leaders don't share the Trump administration's position on climate.

Trump last month did not reaffirm the Paris agreement to which former-President Barack Obama agreed in 2016.

World leaders including Trump did reach a common statement this weekend about the other contentious issue at the summit, trade.

Climate and trade were two of the most contentious issues, in part due to the assertive stance taken on both by Trump.

The president has said trade must be fair as well as open and must benefit American companies and workers.

He has focused on trade relationships where other countries run large surpluses with the U.S., meaning they sell more to U.S. consumers than they buy from American companies.

The G-20 typically denounces protectionism, or the use of unfair means to keep out foreign competitors and protect domestic workers and companies.

That stance has been kept, but it has been expanded to include references to the use of "legitimate trade defense instruments" when a country is faced with subsidized or otherwise unfair competition from a trade partner.

Defensive measures are sometimes allowed under the current global trade rules supervised by the World Trade Organization.

The Associated Press contributed to this report.