Libssh2 with WinCNG unable to obtain public key from private key with passphrase

Question

I'm using libssh2 with WinCNG. It is failing to extract public key from a private key + passphrase pair. I see in wincng.c

_libssh2_wincng_load_pem(LIBSSH2_SESSION *session,
                         const char *filename,
                         const char *passphrase,
                         const char *headerbegin,
                         const char *headerend,
                         unsigned char **data,
                         unsigned int *datalen)
{
    FILE *fp;
    int ret;

    (void)passphrase;

    fp = fopen(filename, "r");
    if (!fp) {
        return -1;
    }

    ret = _libssh2_pem_parse(session, headerbegin, headerend,
                             fp, data, datalen);

    fclose(fp);

    return ret;
}

passphrase is no where used when private key file is read.

Is it possible to use a private key + passphrase pair to extract publick key using libssh2 WinCNG?

Thanks in advance