Russia indicated it is prepared to wait “half a century” or longer for the U.S. to reverse course on sanctions, the Associated Press reported. The country’s latest defiant statement came as the U.S. imposed a new round of sanctions over the Russian annexation of Crimea in March.

A representative of Russia’s foreign ministry said Saturday it was useless for the U.S. to continue sanctions, even as its currency, the ruble, crumbles and rumors spread of a possible military coup while the country wrestles with economic turmoil. The ruble lost 11 percent against the U.S. dollar last Tuesday, representing its largest one-day decline since the Russian financial crisis in 1998, as Reuters reported. The currency’s value has fallen more than 50 percent this year.

U.S. Secretary of State John Kerry said sanctions could quickly be lifted if Russian President Vladimir Putin would agree to ease tensions in the Ukraine conflict. “These sanctions could be lifted in a matter of weeks or days, depending on the choices that President Putin takes,” Reuters quoted Kerry as telling reporters in London.

Russia’s foreign ministry pledged the country will stay in the region as long as it takes for the U.S. to recognize its historic right to the Crimean peninsula, noting in a statement that “the United States and Canada still cannot get over the results of a free vote in Crimea in March,” AP reported. The referendum was almost universally condemned by Western governments as illegal and held under the guns of Russian troops, as the news agency said.

U.S. President Barack Obama approved the latest restrictions on Russia over Crimea Friday, after several other rounds of sanctions imposed this year.

Canada followed suit, announcing travel bans on dozens of individuals as well as restrictions on the export of technology used in the Russian oil industry, AP reported.

Moscow struck back rhetorically, saying the new sanctions would not have the desired effect and that it was working on unspecified measures to retaliate.

In its statement, the Russian foreign ministry mentioned Cuba, with which Obama restored diplomatic relations this week after five decades of frosty relations. “The White House took half a century to admit that blockading Cuba with sanctions was useless,” the ministry said. “Well, we can wait, too.”