For the second day in a row, Iran sought on Friday to claim innocence in the attacks on two oil tankers in the Gulf of Oman, saying it was alarming and wrong of the United States to blame Tehran.
The incident has raised concerns about a new confrontation in the vital oil shipping route.
US actions pose a serious threat to stability in the Middle East, Iranian President Hassan Rouhani told the leaders of a China-led security bloc in Bishkek, Kyrgyzstan.
Rouhani did not mention the attacks but focused his criticism on US President Donald Trump's withdrawal last year from world powers' 2015 nuclear deal with Iran.
The Middle East situation requires closer ties between Iran and Russia, Rouhani said.
Chinese President Xi Jinping told his Iranian counterpart that China will promote steady development of ties with Iran no matter how the situation changes, Chinese state media said.
The official Xinhua news agency said Xi made the comment in a meeting with Rouhani on the sidelines of the Shanghai Cooperation Organization summit in Bishkek.
The United States has blamed Iran for the attacks on the two oil tankers in the Gulf of Oman.
But Iran said on Friday it was responsible for maintaining the security of the Strait of Hormuz in the Gulf, adding that blaming Tehran for the attacks was alarming.
"We are responsible for ensuring the security of the Strait and we have rescued the crew of those attacked tankers in the shortest possible time," Foreign Ministry spokesman Abbas Mousavi said.
"Obviously, accusing Iran for such a suspicious and unfortunate incident is the simplest and the most convenient way for (US Secretary of State Mike) Pompeo and other US officials. These accusations are alarming."
