The 2015 accord for the first time united most of the world in a single agreement to mitigate climate change.
It was signed by 195 countries out of 197 in a UN group on climate change, with Syria and Nicaragua abstaining.
In a tweet on Wednesday, Mr Trump said he would announce his decision within the “next few days”.
Climate change, or global warming, refers to the damaging effect of gases, or emissions, released from industry and agriculture on the atmosphere.
The Paris accord is meant to limit the global rise in temperature attributed to emissions.
Countries agreed to:
Keep global temperatures “well below” the level of 2C (3.6F) above pre-industrial times and “endeavour to limit” them even more, to 1.5C
Limit the amount of greenhouse gases emitted by human activity to the same levels that trees, soil and oceans can absorb naturally, beginning at some point between 2050 and 2100
Review each country’s contribution to cutting emissions every five years so they scale up to the challenge
Enable rich countries to help poorer nations by providing “climate finance” to adapt to climate change and switch to renewable energy
Why does Trump object?
Mr Trump has previously called climate change “a hoax” devised by the Chinese government.
He promised to “cancel” the Paris deal during his election campaign last year, saying it was “bad for US business” because it allowed “foreign bureaucrats control over how much energy we use”.
German Chancellor Angela Merkel told reporters the climate conversations were unsatisfying. The leaders of the other G7 nations — France, Japan, Canada, the United Kingdom and Italy — all urged Trump to remain a part of the 2015 agreement.
Aides to Trump said he was listening with an open mind to the other leaders’ arguments about Paris, but didn’t feel obligated to heed their calls to remain within the pact. After he returned to Washington, Trump lashed out at Merkel over other matters, including NATO funding and Germany’s trade deficit.