CVS Merge between branches in two different repositories

[Muk]

Folks,

  I have two different repositories ( basically two trunks ) for the
same project. There are branches on both. I would like to merge branch
A on trunk 1 with branch B on trunk 2. Is this possible with cvs merge?
I tried to do this - >

with trunk 2 as CVSROOT, cvs co -r B <proj>.
with trunk 1 as CVSROOT, cvs update -j A <proj>
with trunk 2 as CVSROOT, cvs diff -r B <proj>

I got a lot of messages saying the comparison is not possible. When I
did a CVS status on files in the working directory, the working
revision had been changed to "New File!".

Please advise if there is a way to merge the two branches in two
different trunks.

Thanks,
Mukund