Access Denied (Service: Amazon S3; Status Code: 403; Error Code: AccessDenied – Amazon Web Sevices

In a Spring Boot project, I try to get list of buckets. I don’t have a bucket yet. Error is as follows:

Access Denied (Service: Amazon S3; Status Code: 403; Error Code: AccessDenied

I created the access & secret keys an hour ago. I tried to delete and re-create bu no chance. Is there anything missing?

AWSCredentials credentials = new BasicAWSCredentials(
    "myaccesskey", 
    "mysecretkey"
    );

    AmazonS3 s3client = AmazonS3ClientBuilder
    .standard()
    .withCredentials(new AWSStaticCredentialsProvider(credentials))
    .withRegion(Regions.US_EAST_1)
    .build();

    try{
        List<Bucket> buckets = s3client.listBuckets();
        
        for(Bucket bucket : buckets) {
            response += bucket.getName();
        }
    } catch (Exception exception) {
        System.out.print(exception);
    }