Russia will retaliate in a reciprocal manner if the United States does not heed its demands for a return of diplomatic assets, Foreign Minister Sergei Lavrov has said.
"We hope that the United States, as a country which promotes the rule of law, will respect its international obligations," Lavrov said after a meeting in Brussels with EU foreign-policy chief Federica Mogherini on July 11.
"If this does not happen, if we see that this step is not seen as essential in Washington, then of course we will take retaliatory measures. This is the law of diplomacy, the law of international affairs, that reciprocity is the basis of all relations."
In December, the United States seized two Russian diplomatic compounds and then-President Barack Obama ordered the expulsion of 35 Russians over what he said was their involvement in hacking to interfere in the U.S. presidential election campaign.
Moscow denied the allegations and said then it would wait to see if relations improved under incoming President Donald Trump.
Lavrov on July 11 declined to answer when asked if that meant that Russia would expel U.S. diplomats and seize diplomatic property. "We are now thinking of specific steps," he said.
Lavrov's statements came after he said earlier on July 11 that "the situation is outrageous" during a visit to Austria.
Citing a Russian diplomatic source, Russian daily Izvestia said Moscow was considering expelling around 30 U.S. diplomats and taking over two U.S. diplomatic compounds in Moscow and St. Petersburg.
Izvestia said the Russian government was frustrated that President Vladimir Putin's first meeting with Trump in Hamburg last week had failed to resolve the diplomatic row.
Their discussions far exceeded the original time limit, ranging from cybersecurity to the conflicts in Syria and Ukraine. Trump described the talks soon afterward as "very, very good."
With reporting by Reuters and Rikard Jozwiak in Brussels