CARACAS, May 21 (Xinhua) -- The "criminal" financial blockade by the United States against Venezuela puts the lives of children who received transplants in Argentina at risk, Venezuelan Foreign Minister Jorge Arreaza said Tuesday.

Via his Twitter account, Arreaza said that the state oil company PDVSA, which is on the U.S. sanction list, has been supporting health programs sending the children to Argentina.

"It has been impossible to transfer the funds to continue with the treatments," he wrote.

He has sent a letter to the UN High Commissioner for Human Rights Michelle Bachelet to highlight the plight of five Venezuelan children receiving treatment in Argentina. The letter was also signed by the parents of the children.