Th upper end of politics might but other reasons have been given - relationships and Trump willing.
Starmer has a very heavy schedule talking to a number of people at the UN meeting,. In fact he has been out and about in several countries. Grey is back with him.
Perhaps Two Tier has learnt a lesson from The Tories. The Tory leaders slagged off Trump before he was elected, then had to rebuild bridges with him when he caught them out by actually becomming president.