MOSCOW, February 27 - RAPSI. Children's Rights Ombudsman Pavel Astakhov said he will not rescind his earlier statements concerning an adopted Russian child killed by his new U.S. family.

"Neither diplomats nor the children's ombudsman will backtrack on this issue, and we are determined to establish the truth," he told the media on Wednesday.

The stance of U.S. Secretary of State John Kerry, who has pledged to ensure transparency in the adoption of Russian children, is worthy of respect, he said.

"Our task today is to tone down our emotions," Astakhov said. "I am primarily referring to those who are engaging in provocations and attributing things to us that we didnt say or do. We should combine efforts with the Foreign Ministry to develop rules that will ensure the thorough investigation and monitoring of how Russian children are living with their American families."

Astakhov tweeted on February 18 that three-year-old Maxim Kuzmin had been killed in Texas by his adoptive mother. He also said the child had been given powerful "psychotropic substances" and beaten badly before his death, which reportedly occurred on January 21 after he was brought to hospital.

Kuzmin's brother remains in the adoptive family.