PL/SQL :: Inserting Data Into Updated Table

I have a table created with the following code:

CREATE TABLE CLIENT
(
CLIENT_ID NUMERIC(2),
CLIENT_NAME VARCHAR2(25),
CONTACT_LAST_NAME VARCHAR2(15),

[Code]...

I have altered the table to have the following:

ALTER TABLE CLIENT
ADD CLIENT_CITY VARCHAR2(25);

I am trying to insert new data into said table that was updated:

INSERT INTO CLIENT
(CLIENT_CITY)
VALUES
('Mount Pearl')
WHERE CLIENT_ID = 1;

Then I get the following error:

Error starting at line 1 in command:

INSERT INTO CLIENT
(CLIENT_CITY)
VALUES
('Mount Pearl')
WHERE CLIENT_ID = 1
Error at Command Line:4 Column:15
Error report:
SQL Error: ORA-00933: SQL command not properly ended
00933. 00000 - "SQL command not properly ended"
*Cause:   
*Action: