WARSAW, April 16 (Reuters) - Unilateral action on trade by European Union member states is unacceptable, the bloc's executive said on Sunday, after Poland and Hungary announced bans on grain and other food imports from Ukraine to protect their local agricultural sectors. Poland's Agriculture Minister Robert Telus was quoted as saying on Sunday that the ban was necessary to "open the eyes of the EU to the fact that further decisions are needed that will allow products from Ukraine to go deep into Europe, and not stay in Poland. See here for a complete list of exchanges and delays