GENEVA, July 17 (Reuters) - Here are some comments from international organisations working in the fields of aid, international trade and food security on Russia's decision to halt its participation in the Black Sea grain deal.

Ngozi Okonjo-Iweala, head of the World Trade Organization (WTO), wrote on Twitter:

"Deeply disappointed at the termination of the Black Sea Grain Initiative and the interruption of the grain trade from Ukraine... Black Sea trade in food, feed and fertilizer is critical to the stability of global food prices. Sad to say that poor people and poor countries are hardest hit. Let's keep hope alive on renewal."

Jan Egeland, Secretary General of the Norwegian Refugee Council, told Reuters:

"It's completely reckless to not renew the deal. They have to sit down again at the negotiating table... Rations are being cut to children every day now across the world – it is utterly dramatic and this (deal) was one of the few glimmers of hope in this age of Biblical starvation."

Cindy McCain, head of the World Food Programme, wrote on Twitter:

"The Black Sea Initiative has been a lifeline to millions during an unprecedented global hunger crisis. Yet today, Russia chose to terminate it. Struggling families around the world do not deserve to be collateral victims of this war. We must find a way forward."

Nana Ndeda, Humanitarian Advocacy and Policy Lead at Save the Children, said in a statement:

"Failure to renew the Black Sea Initiative today is a huge, life-threatening blow to vulnerable children living in countries in Africa and the Middle East who rely on grain staples. The grain deal was a lifeline to millions of boys and girls facing devastating hunger. Not renewing this initiative will prove catastrophic for children around the world and cost thousands of lives."

David Miliband, President and CEO of the International Rescue Committee, said in a statement:

"The International Rescue Committee (IRC) is deeply alarmed at Russia's withdrawal from the Black Sea Grain Initiative, putting the future of the grain exports from the region at risk- a decision which will be most painfully felt by the 349 million people around the world facing food insecurity today. From Ukraine to Somalia, IRC's clients are facing the ripple effects on food and energy prices of 500 days of war. The expiration of the deal risks holding global food security at ransom."

Alberta Guerra, Food Policy Expert at ActionAid, said in a statement:

"It's really alarming to see Russia pull out of the Black Sea grain deal. Global food prices have been declining in the last months and with it the cost of cereal, thanks very much to this initiative. Without it, it's likely we will see prices rise again, further exacerbating the harsh situations faced by many vulnerable countries already facing acute hunger." (Reporting by Emma Farge, Gabrielle Tétrault-Farber, Leah Douglas; Editing by Christina Fincher)