Russia is dialing up its warnings to foreign leaders regarding interfering with its invasion of Ukraine.
President Vladimir Putin says any countries that intervene will be met with a "lightning-fast" military response.

Putin told Russian lawmakers on Wednesday that all decisions regarding potential retaliation have already been made. He said they have all the tools for it...things no one else can boast of. He said they are not bragging and that they will use them if they have to.

When Russia started its invasion against Ukraine, Putin boasted that even after the collapse of the Soviet Union, Russia is still a nuclear power.

Regarding Ukraine, he stressed that if Russia identifies any threats, the country will immediately launch a counterattack...something many in the west believe could involve nuclear weapons.

The Pentagon's press secretary John Kirby criticized remarks by Russian leaders, saying the rhetoric raising the specter of nuclear confrontation is irresponsible.

He says the US monitors those threats every day, remaining comfortable that it has the appropriate nuclear deterrent posture in place. He also says the US is confident in its ability to defend its homeland as well as its allies and partners.

In Mariupol, about 1,000 civilians along with hundreds of Ukrainian troops are still believed to be trapped in a steel plant. Moscow says the facility is completely surrounded.
Elsewhere in the city, satellite images appear to show at least three mass graves so far.
A Ukrainian journalist told NHK a witness says they saw bodies being thrown directly into a hole from a Russian military truck...almost like they were dumping logs.