Tension and fears are mounting
And here are some other pieces that break down what is happening:
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Above all, we believe that the Ukrainian people should be able to decide their own future.
But nothing official is on the books. Lavrov will meet with Kerry on Wednesday.
The U.S. plane landed in Paris on Tuesday night.
The Budapest Memorandum is a pact of security assurances signed by the United States, United Kingdom, Ukraine, and Russia in 1994.
"Putin needs to know that the security guarantee to those countries is strong and everlasting. That's a message that the President of the United States is uniquely capable of giving."
“We do not expect the current Russia-Ukraine situation to have any impact on our civil space cooperation with Russia," NASA spokesman Allard Beutel said in a statement.
He added that the ISS program's success is based on the "mutual dependence" of everyone involved.
"As such, it is in the best interest of all ISS partners not to allow disruption of operations that have maintained continuous human presence on orbit for over a decade," he said.
He called the relationship between NASA and its Russian counterpart, Roscosmos, "professional, beneficial, and collegial."
The ISS program includes members from Japan, Canada and some other European countries.
Stephen Hadley, former National Security Adviser for President George W. Bush's administration, told Anderson Cooper that the Vladimir Putin he watched at the news conference Tuesday was the same man he dealt with back in 2008 and earlier.