Web Service Reference error : Could not create SSL/TLS secure channel.

Hi, I've trying to add the web service reference into my project. But every time it's show an error. Error is give below

"There was an error downloading 'https://ecomtest.*****.com/ecomws/****ecomtxn?wsdl/_vti_bin/ListData.svc/$metadata'.
The request was aborted: Could not create SSL/TLS secure channel."

Can anyone give me any solution for this error. I'm using Visual Studio 13. 

Thanks in advance.