Claim can be used to mean many things a) to say that something is true when some people may say it is not true. 'He claims to be an expert.' b) to say that you have something. 'He claims to have a connection to the royal family.' c) To say that something belongs to you or that you deserve something. 'The terrorist group claimed responsibility for the attack.' d) to say you have a legal right to be given something. 'They claimed asylum' e) to take something that belongs to you. 'She claimed her luggage and left the airport.' f)'To cause the end of someone's life. The accident claimed seven victims. (seven people died in the accident) and g) used to say that someone's time or attention is being given to something. 'An urgent message claimed his attention ( demanded/required his attention) Announce is not similar to claim except that both can be used to make something known in public but announce is used to make facts public .'The government announced a cut in taxes.' and claim to say that something belongs to you. as in my example c) 'Announce' is also used to say something in a loud and definite way. 'He suddenly stood up and announced that he was leaving.' or to say in a formal or official way that someone or something has arrived. 'A man at the door announced each guest.'

claim = 声称 announce = 布