Error during opam initialization

[shrey27tri01]

I understand this is an old repository, but I am not able to find a solution to the problem I am facing. During the initialization step, on running opam init --compiler=4.12.0 (the Ocaml version I have is 4.12.0), I get the following error:

No configuration file found, using built-in defaults.
Checking for available remotes: rsync and local, git.
  - you won't be able to use mercurial repositories unless you install the hg command on your system.
  - you won't be able to use darcs repositories unless you install the darcs command on your system.


<><> Fetching repository information ><><><><><><><><><><><><><><><><><><><><><>
[ERROR] Could not update repository "default": OpamDownload.Download_fail(_, "Curl failed: \"/usr/bin/curl
        --write-out %{http_code}\\\\n --retry 3 --retry-delay 2 --user-agent opam/2.1.2 -L -o
        /private/var/folders/vp/dsq0rbzs2lqdkn6fwcxxl5wr0000gp/T/opam-17560-a56e56/index.tar.gz.part --
        https://opam.ocaml.org/index.tar.gz\" exited with code 60")
[ERROR] Initial download of repository failed.

It would be great if I could be pointed to some resources which could help me.

Specifications:
Opam version 2.1.2
Ocaml version 4.12.0
Operating System: macOS High Sierra version 10.13.6

Please let me know if any other information is needed.