U s expresses objection to palestinian as u n envoy to libya

I think there may be some confusion here. The United States has not expressed an objection to a Palestinian as the UN Envoy to Libya. In fact, the UN has not appointed a Palestinian as the Envoy to Libya.

However, the United States has been critical of the UN's treatment of Israel and has often vetoed or abstained from votes on resolutions that are perceived as anti-Israel. This has led to tensions between the US and the UN, particularly on issues related to the Israeli-Palestinian conflict.

It's possible that you may be referring to a specific incident or statement made by a US official that you are not aware of. If you could provide more context or clarify what you are referring to, I'd be happy to try and help you understand the situation better.