Administration officials said the crunch sit-down set for Tuesday had "been postponed" and may now take place next week.
'We are now reviewing issues related to the agreement, and expect to have a decision by the time of the G7 Summit, late May-ish, if not sooner, ' White House Press Secretary Sean Spicer said in March.
The European Union has been scrambling to persuade Trump to stick to the deal.
The 11-day haggle on the nuts and bolts of the deal is meant to start drafting a "rulebook" to guide member countries in the practical execution of the pact.
John Kerry, then secretary of state, speaking at the United Nations signing ceremony for the Paris Agreement climate change accord in New York, April 22, 2016. But, like that larger meeting, the session between Ivanka Trump and Pruitt was postponed.
Speaker after speaker in Bonn reiterated the deal must not be "renegotiated" - a proposal of Trump's Energy Secretary Rick Perry.
It could also have a negative impact on Trump's careful diplomacy with China, which the White House wants on-side to tackle North Korea's nuclear and ballistic missile programmes.
Meanwhile, at a summit in Milan, Italy, focused on climate change and food availability, President Barack Obama defended the Paris agreement earlier Tuesday, saying the United States must show leadership and not "sit on the sidelines".
Trump will "come to a decision on what's in the best interest of the United States using the expertise that surrounds him", he said.
Australian prime minister says Trump treated him like family
After the meeting, Turnbull described his relationship with Trump as "more family than formal". Together, the United States and Australia are building a more secure and stable world.
"President Trump emphasized his desire to work closely with President-elect Macron in confronting shared challenges, and noted the long and robust history of cooperation between the United States and its oldest ally, France", the statement said.
"It would be hard, crazy, to go against public opinion, against the domestic will, and the will of the global community", Mezouar said in Bonn.
Some fear a U.S. U-turn would dampen enthusiasm among other signatories for more efforts on emissions-cutting targets.
The Paris accord calls for limiting the global average temperature increase since the industrial revolution to 3.6 degrees or less - a goal that has been called ambitious.
The forum's budget is on the Bonn agenda.
Many nations and NGOs are urging Trump to stay in the global agreement.
Even fossil fuel giants including Shell and ExxonMobil are expressing support for the Paris agreement in the lead up to the administration's decision, with the latter calling it "an effective framework for addressing climate change".
It was not clear to what extent the U.S. team was actively taking part in the latest talks. "But it is not on the agenda, so we can not discuss it".