>>> Today, Poland's president
was at the site of that deadly
missile strike that struck
inside his country.
CNN has learned that Ukrainian
officials are also on the ground
there, joining U.S. And Polish
investigators.
Ukrainian president zelenskyy
said it will not be possible to
draw conclusions about who is
responsible for the missile yet.
>> But he added, he is convinced
it is Russia who is to blame.
President Biden said that the
evidence indicates otherwise.
CNN also has learned that the
U.S. Is running low on high-end
weapons systems and ammunition
to send to Ukraine.
We have Natasha Bertrand and
Oren Liebermann up with us next.
Natasha, you're first on the new
reporting into the investigation
on that missile.
What are you learning?
>> Reporter: When news broke
that this missile had struck
Poland killing two people, we're
learning that there was really a
scramble, and underscoring the
urgency there is the fact that
president Biden who was in Bali
at the g20 summit.
We saw him speaking to president
Duda, Biden was dressed casually
in khakis.
And the vice president speaking
to their counterparts with
trying to get information on
what had happened, of key
importance, of course, learning
whether or not this had been a
deliberate attack on Poland, the
nato ally.
As news came in, as intelligence
came in, as they spoke to their
Polish counterparts it's
becoming increasingly clear,
we're told according to
intelligence, this was not a
deliberate attack.
That actually, it was more
likely an accidental strike by a
Ukrainian missile.
What we're told that the
intelligence that the U.S. Had
been receiving based on only six
of debris at the site, what the
poles had been looking at and
telling Americans it all pointed
to one direction that this was
an anti-air missile that the
Ukrainians had launched.
So, one of the really key issues
that night was kind of getting
everyone on the same page about
what had happened.
And that includes, of course,
the Ukrainians, guys.
>> So, Oren, you've been
reporting also on the low
weapons stockpile that the U.S.
Has to send to Ukraine.
And the effect that could have.
So what does that mean?
>> Reporter: So critical
distinction, we'll start here,
is the U.S.' stockpile, what it
keeps in plans for emergency and
contingency situations that
remains and will be untouched.
The question is the excess here,
what the U.S. Has available to
send.
And these according to sources
who spoke to CNN and officials
were finite to begin with.
We're now nine months into the
war, we've seen repeatedly at
the pace at which the U.S. Sends
the ammunition, the stinger, and
the 155 artillery ammunition.
All of this has been going over
in plane loads in very large
numbers since the beginning.
And according to our sources
some of the stocks of excesses
that the U.S. Could send are
beginning to dwindle, because
they were finite to begin with.
What we just heard from Lloyd
Austin and chairman mark Milley,
the aid, the supplies will
continue.
But there is now this
international coalition, we've
seen over the past three months,
the Ukraine content group as
it's called to find available
stocks and make sure they can
get to Ukraine.
Even if that involves putting
together a system from one place
and ammunition from another.
That's part of the solution.
The U.S. Is also trying to ramp
up its defense industrial base,
making sure it can produce more
weaponry and speed that up as
needed.
The U.S. For the first time in
20 years isn't at war after the
withdrawal from Afghanistan, so
there wasn't this great demand
to keep producing.
But as we're seeing with U.S.
Providing Ukraine, it's time to
speed up that production once
again since the expectation of
this war continues.
>> Natasha Bertrand, Oren
Liebermann, thank you both very
much.
Let's bring in the former
ambassador to nato, he now
serves on the Chicago counsel of
global affairs.
Mr. Is ambassador, thanks for
being here.
It's interesting to hear Natasha
talk about the scramble, they
had to wake up president Biden,
he was out of the country, and
everyone had to be alerted and
just how much cooler heads
prevailed in that moment of
confusion.
And did not escalate.
Is that normally what happens
when a bomb falls on a nato
country?
>> Well, you would hope so.
You would hope that if this
happens again, the same kind of
deliberative effort is made to
find out what the facts are.
The problem with war and the
problem with having so many
missiles flying across the skies
of Ukraine that we saw in the
runup to this accident is that
things can go wrong.
And if they do go wrong, you got
to figure out what's going on.
So, the system works, in many
ways.
It churned through the process.
An explosion happened.
The poles went very quickly to
the site to figure out what was
going on.
We looked at all of the
intelligence that we might have,
intercepts of conversations.
Trajectories of missiles that
were being flown at the time.
In order to get as much
information as possible.
And at the same time, the U.S.
Government and other governments
were out there in force,
starting with the president
himself throughout our
ambassador in Poland or
ambassador at nato were all
making the case to say, let's
find out what is going on before
we decide how to respond.
That can come later.
Depending on what the outcome of
this investigation is, that can
come later.
So, I think cooler heads prevail
which is what you would hope
from your leaders.
And not have people start
immediately thinking about
retaliation and how to hit the
Russians before you know what
was going on.
And I think that's what
happened.
>> Ambassador daalder, what do
you think about the Ukrainians
joining this investigation?
President zelenskyy said they'll
be there at the morning at the
site in Poland.
They're not a disinterested
party here.
And the president's already said
that it was a Russian missile.
Do you think they should be
there on scene, participating in
the investigation?
>> Yeah.
I think it's perfectly fine for
them to be part of the
investigation which is being led
by the poles.
There are U.S. Personnel on the
ground to help identify it,
presumably others as well.
Having the Ukrainians there is
appropriate, given that it may
have been and looks like it was
a Ukrainian missile.
Certainly, from their territory,
or across their border.
Just to point out, I think
president zelenskyy went a
little farther ahead on the skis
when he immediately said it was
a Russian missile.
And sort of cornered himself and
made it more difficult for him
to admit the possibility that it
might have been an accident.
At the same time, let's be
clear, none of this would have
happened, unless the Russians
had invaded Ukraine.
And had launched close to 100
missiles, the largest number of
missiles, in the war to date.
On all kinds of Ukrainian
targets.
So, the real fault here is with
Russia.
It's not with Ukraine.
This is an accident that it
couldn't -- it couldn't have
helped.
It means we need to provide,
more better capable air defense
systems to the Ukrainians.
And probably a lesson that we
learned that perhaps the
government, too, can learn is
when something like this
happens, let's find out what the