Moscow: Russia`s parliamentary speaker on Friday denounced new US sanctions against Moscow as "disconnected from reality", and charged the Ukraine crisis was an excuse for Washington to drum up tensions with its Cold War-era foe.
"The sanctions announced by President (Barack) Obama are already disconnected from reality," State Duma Sergei Naryshkin was quoted as saying by Russian news agencies.
Obama said the sanctions would hit the defence, finance and energy sectors in response to Russia`s "illegal actions" in Ukraine.
Fresh EU sanctions against Moscow also took effect on Friday.
"For them, the most difficult internal Ukrainian conflict, crisis, confrontation is just a pretext -- this is obvious," Naryshkin said.
"If it did not happen they would find another (excuse). This is sad but true."
The parliamentary speaker also warned the sanctions could hamper a fragile week-long ceasefire between Ukraine and Kremlin-backed separatists. "What are they thinking?" he said, referring to US officials.
Obama said Washington would detail the new sanctions on Friday. The EU measures target major Russian oil firms, defence companies and state-owned banks, as well as individuals linked to President Vladimir Putin.
The Russian ruble hit a new low against the dollar on Friday, as new EU sanctions on Moscow entered force.
The Moscow stock markets fell, with the ruble-denominated Micex down 0.10 percent and the dollar-denominated RTS down 0.51 percent.
A ceasefire signed last Friday between Kiev and separatist rebels in Ukraine`s industrial heartland has so far held, despite accusations of violations on both sides.
The conflict has killed more than 2,700 people since April, forced at least half a million from their homes and sent tensions between Russia and the West soaring to post-Cold War highs.