Trump's comments came after Nikki Haley, US ambassador to the UN, sent threatening letters to UN member states, urging them to vote against the motion.
US President Donald Trump has threatened to cut aid to countries that vote in favour of a draft UN resolution condemning the US decision to recognise Jerusalem as the capital of Israel.
Trump said at the White House on Wednesday the US would be “watching those votes” in the General Assembly.
Reuters news agency quoted Trump as saying: “They take hundreds of millions of dollars and even billions of dollars, and then they vote against us. Well, we’re watching those votes. Let them vote against us. We’ll save a lot. We don’t care”
The UN General Assembly will hold an emergency session on Thursday to vote on the controversial US decision.
The motion is expected to pass easily in the 193-member UN body, but it will be non-binding.
Trump’s comments came after Nikki Haley, US ambassador to the UN, sent threatening letters to UN member states, urging them to vote against the motion.
“The president will be watching this vote carefully and has requested I report back on those who voted against us,” Haley wrote. “Thank you for your consideration, and please do not hesitate to contact my team with any questions or concerns.”
The letter continued: “As you know, the General Assembly is considering a resolution about President Trump’s recent decision on Jerusalem. As you consider your vote, I encourage you to know the president and the US take this vote personally.”
The UN General Assembly is set to meet tomorrow at 3pm GMT, for an emergency discussion on Jerusalem. Turkey and Yemen requested the meeting after the US vetoed an Egyptian-sponsored draft resolution at the UN Security Council, which was backed by all 14 other council members.