The Prime Minster returned from his holiday in Lanzarote after Tata Steel announced plans to sell its entire UK operations.
Thousands of jobs have been put at risk.
More than 96,000 people have signed a Labour petition calling for Parliament to be recalled early.
Mr Cameron tweeted: “Today I have met with ministers to discuss the future of Port Talbot.
“Workers and their families face a worrying time, and our priority is to help those likely to be affected.
“During this process, we are committed to working with the Welsh gov’t and Tata on a long term sustainable future for British steel making.“