Russia-Ukraine updates: Putin suspends key US-Russia nuclear treaty

Moscow has been "cruelly" targeting Ukrainian civilians by launching attacks against utilities during the winter, the U.S. Embassy in Kyiv said on Thursday.

The rebuke came as Russia fired missiles at cities throughout the country on Thursday. The General Staff of the Ukrainian Army said 69 missiles were launched, fewer than the 100 missiles that officials had estimated earlier in the morning. Officials said 54 missiles were intercepted.

Two civilians were killed as a result of shelling in the Kharkiv area, according to the region's governor.

"The Kremlin continues its escalating campaign of missile attacks, cruelly wielding cold & dark against" Ukrainians, U.S. Embassy officials said on Twitter. "Families are again hunkering down as critical infrastructure & other targets across the country are attacked."

Air raid sirens started wailing before 6 a.m. local time across Ukraine, sending residents scrambling into underground shelters in several cities. Missiles landed in Kyiv, Kharkiv, Odesa, Lviv and Zhtomyr.

Ukraine's defense systems intercepted some missiles, including 16 that were shot down near Kyiv, the capital, Mayor Vitali Klitschko said. Two homes in Kyiv were damaged by falling debris and three people were injured, he said.

Ukraine's Ministry of Defense said Russia had been "saving one of the most massive missile attacks since the beginning of the full-scale invasion for the last days of the year."

"They dream that Ukrainians will celebrate the New Year in darkness and cold," officials said. "But they cannot defeat the Ukrainian people."

-ABC News' Britt Clennett and Joe Simonetti

Russian forces early on Thursday launched a missile strike on Ukraine.

Oleksiy Arestovych, an adviser to Ukrainian President Volodymyr Zelenskyy, first posted on Twitter that more than 100 rockets were fired in several waves. Some rockets were reportedly fired from carriers in the sea, while others were reportedly fired by at least a dozen fighter aircraft.

Another presidential adviser, Mykhailo Podolyak, claimed on Twitter that more than 120 missiles had been launched "by the 'evil Russian world' to destroy critical infrastructure & kill civilians en masse."

The General Staff of the Ukrainian Army later said 69 missiles were launched, fewer than the 100 missiles that officials had estimated earlier in the morning.

At least one loud explosion was heard in Kyiv, where air raid sirens were ringing for several hours on Thursday morning.

-ABC News' Edward Szekeres, Britt Clennett and Joe Simonetti

Editor's note: This post has been updated to reflect an update issued by the Ukrainian Army on the number of missiles launched.

Russia has rejected a proposal from Ukraine to hold a "peace summit" in February, according to a Kremlin official.

"There is no 'peace plan' for Ukraine for now, that's for starters," Kremlin spokesman Dmitry Peskov told reporters Wenderday. "Besides, there can be no 'peace plan' for Ukraine, which disregards today's realities on Russian territory, the entry of new regions, four of them, into Russia."

Peskov was apparently referring to recent Ukrainian drone attacks inside Russia, including one this week at the Engels Air Force Base in southern Russia that killed three Russian soldiers.

On Monday, Ukraine's foreign minister said in an interview with The Associated Press that he would like to have a peace summit in February, the one-year anniversary of the war, and would like it to be held at the United Nations.

"The United Nations could be the best venue for holding this summit, because this is not about making a favor to a certain country," Dmytro Kuleba told the AP. "This is really about bringing everyone on board and there is no better place than the United Nations to do that."

-ABC News' William Gretsky

Russian President Vladimir Putin signed a decree Tuesday that not only rejects a price cap on the country's oil but bans sending crude and other petroleum products to any country that has endorsed the price cap.

The Group of Seven countries, including the United States, agreed on Dec. 3 to impose a $60 per barrel price cap on Russian oil in response to the Kremlin's invasion of Ukraine. Australia and the European Union also agreed to impose the price cap.

The decree Putin signed goes into effect on Feb. 1 and is valid until July 1, 2023.

The decree bans the supply of oil and oil products from Russia to those countries that place a price ceiling on contracts. The decree also forbids the supply of oil to other foreign buyers whose contracts use a price cap mechanism.

The decree includes a clause allowing Putin to overrule the ban in special cases to be determined by the Russian leader.

The price cap on Russian oil implemented by G-7 nations disallows the world's second-largest oil exporter from selling crude at a price above $60 per barrel.

Since the outset of its war with Ukraine, Russia has sold its oil at discounted prices. As of Tuesday, Russian Urals crude was trading at $57 per barrel -- an amount slightly less than the cap. But the price cap aims to ensure that Russian oil sales remain well below global oil prices, which stand at about $80 per barrel.

-ABC News' William Gretsky