Just be careful, some words have different or contradicting meanings in British and American English. For example: (AE- American English, BE- British English)

Sanction
AE: To stop (trade sanctions- no trade)
BE: To give the go ahead

Critical
AE: Verging on a state of emergency
BE: Very important

These are all I could think of but you should get the idea. The saying 'two countries divided by a common language', about Britain and American should also help.