Lavrov told a news conference Washington had disappointed Moscow by blocking a statement condemning "terrorist attacks" near the Russian embassy in Damascus. He said that Washington was threatening international unity in the "war on terror".
"We believe these are double standards," Lavrov said after talks with China's foreign minister.
"And we see in it a very dangerous tendency by our American colleagues to depart from the fundamental principle of unconditional condemnation of any terrorist act, a principle which secures the unity of the international community in the fight against terrorism," he said.
Ties between Washington and Moscow have worsened since Vladimir Putin returned to Russia's presidency last May.
The passage of US legislation intended to punish Russian officials accused of human rights abuses and a Russian ban on American families adopting Russian children have also contributed to the deterioration in recent weeks.
Lavrov made his comments at a joint news conference with Chinese Foreign Minister Yang Jiechi after talks that underlined the closeness of their views on policy in Syria and North Korea.