TASS - Moscow calls on Washington not to meddle with something that is functioning adequately, Russian Deputy Foreign Minister Sergei Ryabkov told TASS on Sunday commenting on US State Secretary Rex Tillerson�s statement on possible amendments or a secondary agreement on the Iranian nuclear program.

"There is an American saying our overseas colleagues often use in such situations: �If it�s not broke, don�t fix it,�" he said. "That�s what I would like to address to the colleagues in the United States."

He drew attention to recurring signals from Washington "in favor of the so-called improvements of the existing agreement and possible supplements to it," he said. "It seems to be a wrong way to follow as the existing documents are working quite efficiently."

"Iran is fully implementing its liabilities, which cannot be said about the United States," the Russian diplomat noted. "What is to be improved in this context is the implementation of the existing agreements by the US side."

Russia calls on the United States to implement the existing agreements on the Iranian nuclear program instead of seeking to amend the Joint Comprehensive Plan of Action (JCPOA), Russian Deputy Foreign Minister said.

"We note recurring signals from Washington in favor of the so-called improvements of the existing agreement and possible supplements to it," he said. "What is to be improved in this context is the implementation of the existing agreements by the US side.".

Russia plans to stress in its contacts with Iran in the near future that it is important to keep the nuclear deal intact, Russian senior diplomat Sergei Ryabkov said.

"Naturally, in our contacts with Iranian colleagues we will stress the importance of keeping the Joint Comprehensive Plan of Action (JCPOA) as it was reached and the importance of it being completely implemented," he said. "I am not ready to provide concrete names or dates but, obviously, we will discuss these topics in the near future."

"As a matter of fact, they [the Iranians] have passed the ball to the US side," he noted.

Earlier on Sunday, US Secretary of State Rex Tillerson said that Washington would continue to cooperate with partners under the Joint Comprehensive Plan of Action (JCPOA), which is geared to settle the crisis around Iran�s nuclear program, seeking to reach a secondary agreement to address other concerns.

On Friday, US President Donald Trump announced Washington�s new strategy against Teheran. Thus, it says that the United States will seek to offset Iran�s destabilizing influence and will call on the international community to get consolidated to exert pressure on Iran�s Revolutionary Guard (Iran's most powerful security and military organization). Apart from that, the US leader refused to recertify the Iran nuclear deal and pledged Washington would seek to amend the JCPOA.

Commenting on this situation, Iranian Foreign Minister Mohammad Javad Zarif said "no one would ever trust the US administration in any long-term talks" if it withdraws from the JCPOA.

Iranian parliament speaker, Ali Larijani, reminded on Sunday that the International Atomic Energy Agency (IAEA) had officially confirmed Iran�s commitment to the deal eight times. In his words, Trump "is not merely ignoring the international agreement but also is demonstrating disrespect to the United Nations."

The deal on Iran�s nuclear program was reached between Iran and six international mediators (the United Kingdom, Germany, China, Russia, the United States, and France) on July 14, 2015. On January 16, 2016, the parties to the deal announced beginning of its implementation. Under the deal, Iran undertakes to curb its nuclear activities and place them under total control of the International Atomic Energy Agency (IAEA) in exchange of abandonment of the sanctions imposed previously by the United Nations Security Council, the European Union and the United States over its nuclear program.