Australia has been urged not to ignore threats of "punitive measures" from top Republicans, as the prime minister lands in the US for one of his most important diplomatic ventures.

Anthony Albanese arrived in New York City on Sunday morning Australian time ahead of a long-awaited United Nations General Assembly meeting where Australia, Canada, France and the UK will recognise the state of Palestine.

But hours before touchdown, a group of top Republican congress members and allies of Donald Trump issued an open letter to the leaders of those nations warning recognition "may invite punitive measures".

"This is something that very well could be a point of contention between the Albanese government and the Trump administration," United States Studies Centre director Jared Mondschein told AA

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