WASHINGTON, Oct 27 (Reuters) - The White House said it is still "realistic" that U.S. President Joe Biden"s signature spending plan could get congressional support by Thursday, but conceded that he may need to depart to Europe without a final deal in hand. Biden is expected to depart Thursday morning to a meeting of G20 nation leaders in Rome and the United Nations Climate Change Conference in Glasgow, Scotland. WASHINGTON, Oct 27 (Reuters) - The White House said it is still "realistic" that U.S. President Joe Biden"s signature spending plan could get congressional support by Thursday, but conceded that he may need to depart to Europe without a final deal in hand. Biden is expected to depart Thursday morning to a meeting of G20 nation leaders in Rome and the United Nations Climate Change Conference in Glasgow, Scotland. The Glasgow conference was expected to be a showcase for Biden to demonstrate U.S. efforts to tackle climate change and ask other countries to adopt similar measures. However, his roughly $1.5 to $2 trillion spending plan aimed at curbing climate change and expanding the social safety net remained mired in intra-party squabbles Wednesday, as did a linked $1 trillion infrastructure bill that also includes climate related measures. "Of course he would like to head on this trip with a deal,” White House spokeswoman Jen Psaki said on Wednesday. However, world leaders are “looking at the president’s commitment” on infrastructure and climate she said, not what"s being passed in Congress. "They’re seeing we’re on the verge of making a deal," she said. Some progressive Democrats in Congress said it seemed unlikely there will be an agreement Wednesday, and suggested fundamental issues, like how to pay for it, remain. "I don"t know," Senator Bernie Sanders said. "But I don"t think so. I"m not quite clear in terms of the revenue package. Every sensible revenue option seems to be destroyed." Biden would need to sign any passed bill into law. He won"t push his trip back substantially to push for it further, Psaki said. "There"s some flexibility in the morning, but I"m not going to suggest he"s going to delay his trip," Psaki said.