Russia-Ukraine updates: Putin suspends key US-Russia nuclear treaty in speech denouncing West

Russian forces have kidnapped Valery Martynyuk, the deputy head of the Russian-occupied Zaporizhzhia nuclear power plant in Ukraine, and are detaining him in an unknown location, Ukraine's state nuclear energy company Energoatom said Tuesday.

Russian forces are allegedly trying to get information about the personal affairs of Zaporizhzhia employees in order to force Ukrainian personnel to work at Russia's state nuclear agency Rosatom as soon as possible, Energoatom alleged in a statement to ABC News.

This incident follows the detention of Zaporizhzhia's then-chief Ihor Murashov on Oct. 1. The International Atomic Energy Agency announced his release on Oct. 3. Murashov later announced he would not return to the plant as its head.

-ABC News' Will Gretsky

Group of 7 leaders met virtually on Tuesday with Ukrainian President Volodymyr Zelenskyy, after Russia launched airstrikes on civilians and civilian areas in response to an attack on the bridge linking annexed Crimea to Russia.

"We condemn these attacks in the strongest possible terms and recall that indiscriminate attacks on innocent civilian populations constitute a war crime. We will hold President Putin and those responsible to account," G-7 leaders said in a joint statement.

The G-7 leaders also accused Russia of "blatantly" violating the U.N. Charter. The leaders also vowed to continue financial, humanitarian, military, diplomatic and legal support to Ukraine.

G-7 leaders also said they would help insure the recovery and reconstruction of Ukraine "including exploring avenues to do so with funds from Russia," according to the statement.

The leaders also condemned the deliberate attacks on Nordstream pipelines in the Baltic Sea and vowed to "act in solidarity and close coordination" to address the impact of Russia's invasion of Ukraine on the global economy.

Ahead of the Group of 20 summit in Bali, Indonesia, next month, Russia indicated it may be open to a meeting between President Joe Biden and President Vladimir Putin, Russian Foreign Minister Sergey Lavrov said in an interview with news agency Interfax.

"We have repeatedly said that we never refuse meetings," Lavrov said, according to Interfax. "If a proposal is made, it will be considered by us."

The White House National Security Council pointed to a comment made by Biden on Thursday outside the White House.

When asked by a reporter if he would meet with Putin, Biden responded, "That remains to be seen."

-ABC News' Anastasia Bagaeva and Ben Gittleson

Russia is in a "desperate" position in its war in Ukraine and is running out of weapons and allies, according to the United Kingdom's top cyber spy.

"We believe that Russia is running short of munitions, it’s certainly running short of friends," Jeremy Fleming, director of the U.K. spy agency GCHQ, told BBC Radio in an interview Tuesday. "Russia and Russia's commanders are worried about the state of their military machine."

"The word I've used is 'desperate,'" he added. "We can see that desperation at many levels inside Russian society and inside the Russian military machine."

Russian President Vladimir Putin has ordered a series of missile strikes across Ukraine in the last 48 hours in retaliation for an attack on the strategically important Kerch bridge into Crimea over the weekend, with Fleming arguing that this will have depleted Moscow's dwindling arsenal.

"Russia, as we've seen in the dreadful attacks yesterday, still has a very capable military machine," he told BBC Radio. "It can launch weapons, it has deep, deep stocks and expertise. And yet, it is very broadly stretched in Ukraine."

-ABC News' Zoe Magee