Handy new fuel for the Americans (6)
I believe the answer is:
useful
'handy' is the definition.
(I've seen this before)
'new fuel for the americans' is the wordplay.
'new' indicates an anagram.
'for' means one lot of letters go next to another (I've seen this in other clues).
'the americans' becomes 'US' (United States).
'fuel' is an anagram of 'eful'.
'eful' put after 'us' is 'USEFUL'.
(Other definitions for useful that I've seen before include "Utilitarian" , "Expedient" , "Suitable for practical purpose" , "Handy, serviceable" , "Advantageous, serviceable" .)