The Biden administration has defended its response to the invasion of Ukraine as it insisted it would not provoke a “potential direct war” with Russia.

       White House press secretary Jen Psaki avoided making any commitment on a no-fly zone over embattle Ukraine.

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       “The no-fly zone requires implementation,” Ms Psaki said when asked about it a briefing on Thursday.

       “It would require, essentially, the US military shooting down Russian planes and causing or prompting a potential direct war with Russia – the exact step that we want to avoid.”

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       Her comments came just hours after Ukrainian president Volodymyr Zelensky begged the US and Europe to install the no-fly zone.

       “I said, ‘If you cannot shut the sky now, then give us a timeline. When will you do it?’” Mr Zelensky said in a televised address.

       “If you can’t provide a timeline now, tell us how many people have to die. How many limbs have to fly off of people’s bodies, so you hear us?

       “How many people will count, and we’ll wait until that moment when you feel comfortable.”

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       Mr Zelensky thanked Western countries for the aid they have given his country, but slammed them for sending it too late.

       “The whole world started making decisions too late. I want to thank the countries that are helping with weapons. We are thankful, but it’s too late.”

       “Strong sanctions right now, I think that was a good start,” he added.

       “Thank God, now we have those sanctions.”