The US says "all options are on the table" in response to a suspected chemical weapons attack in Syria, as Western leaders continue to weigh up military action.

White House spokeswoman Sarah Sanders told reporters that no final decision had been taken on military strikes.

But she said the US holds Russia and Syria responsible for the incident.

The US National Security Council is to meet tomorrow, while UK PM Theresa May has called a cabinet meeting.

Activists, rescue workers and medics say dozens of people died in the rebel‑held town of Douma on Sunday.

But President Bashar al‑Assad's government ‑ which receives military backing from Russia ‑ denies being behind any chemical attack.