Theresa May will visit Wales on Monday to make clear that the Government is committed to helping the country's ailing steel industry.
The Prime Minister will tell the Welsh people she will "always be on your side" and remains committed to keeping the United Kingdom together.
She will meet First Minister Carwyn Jones at the Welsh Assembly in Cardiff and reaffirm that she will "fully engage" with the Welsh government on Brexit negotiations.
Speaking ahead of the visit, the Prime Minister said: "In my first statement as Prime Minister I made clear how strongly I believe in the union. I want to say to the people of Wales that the Government I lead will always be on your side - and that means I will stand up for you and your family against injustice and inequality.
"My Government is committed to helping the steel industry secure a long-term viable future in Wales. The steel industry is vital to the UK and we will do everything we can to look after the workers and wider community as we work with Tata and the Welsh government.
"Whether it's reforming the economy or strengthening our society, we are going to build a better Britain and a nation that works for everyone - not just the privileged few."
The steel industry has been thrown into crisis in recent years, squeezed between rising energy costs and cheap steel from the Chinese.
Last year the Redcar works in Teesside closed, while thousands of workers at Port Talbot in Wales face an uncertain future as talks to save the Tata plant continue.
The EU is Britain's most important steel market and some have raised fears that pulling out could further damage the industry.
Plaid Cymru leader Leanne Wood said Wales should be given "every penny" of lost EU funding after Brexit and suggested the country should be allowed to have its own independence referendum if Scotland pulls out of the UK.
She said: "Plaid Cymru wants every penny of EU funding replaced in the value, and to secure the best possible trade deal for the Welsh economy.
"We are developing a National Mitigation Plan as a party, which will set out exactly what is needed for Wales to be protected from any adverse effects from Brexit.
"In the short-term, we also need Wales to get the same powers as the Scottish Parliament currently has.
"In the event of Scotland becoming an independent country within the EU, we in Wales should also be allowed to decide our own future and explore our own constitutional options as well."