The Chernobyl Children International charity has expressed deep concern over delays to a project aimed at making the site of the Chernobyl nuclear power plant safe.

It was 28 years ago this week when an explosion at the plant sent huge amounts of radiation into the atmosphere.

A €1.4bn internationally-funded construction project aims to build an extra shield around the leaking reactor.

However, the project is now expected to be postponed after Russia indicated that it may withdraw financial support due to the political tension in Ukraine.

The charity's CEO, Adi Roche, said the issue must be put back on the political agenda.

"This is an urgent situation," she told RTÉ's Morning Ireland.

"What we really need is when the negotiations are happening between Russia and Ukraine, we need people like Eamon Gilmore ... to be able to put on the negotiating table the issue of coming back to ensuring that this sarcophagus does get finished and it gets finished on time, for the protection of the entire planet."