How to convert EC public key in PEM format to DER format using openssl

With a public key as **PEM**, how can this be converted to **DER** format using **openssl**? Please note that this is not a x509 certificate. Also this question is about EC (ECDSA) public keys not RSA and using **openssl** not C, C++ or some other programming language

-----BEGIN PUBLIC KEY-----
xxx
-----END PUBLIC KEY-----