'This Week' Transcript: Donald Trump

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ANNOUNCER: Starting right now on ABC's THIS WEEK, breaking news -- new debris found.

Is it from Malaysian Airlines Flight 370 and will it help pinpoint where the plane went down?

Crunch time -- Donald Trump surging in the polls, ahead of the crucial first GOP debate.

Will he keep up his momentum?

Donald Trump is here live.

2016 shocker -- is Joe Biden about to jump into the presidential race?

Plus, hunting outrage -- will Cecil the Lion's death spark new bans on trophy hunting?

And why that American dentist may face criminal charges overseas.

From ABC News, THIS WEEK WITH GEORGE STEPHANOPOULOS begins now.

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JONATHAN KARL, HOST: Good morning.

I'm Jon Karl.

Lots of news to get to this morning, including the countdown to the first Republican debate. Frontrunner Donald Trump will be center stage.

Is he ready?

What's his strategy?

Trump will be with us live momentarily.

But first, we start off with breaking news.

This mysterious piece of debris has just been discovered near where a fragment of a Boeing 777 wing was found just days ago. That piece is set to undergo analysis to see if it is from missing Malaysia Airlines Flight 370.

Let's bring in our aviation expert, Steve Ganyard.

Steve, many are wondering, of course, is this part of that plane?

COL. STEPHEN GANYARD, ABC NEWS AVIATION CONSULTANT: I think we'll have to wait and see, Jon. This needs to go back for forensic testing.

Part of the problem is, is now that we have one piece that's been washed up, every piece of junk that washes up in the Indian Ocean is going to begin to start looking like a piece of a 777.

So we need to continue to go deliberately, slowly, and make sure we look at these pieces in -- in -- by themselves and figure out if this is part of the airplane.

KARL: OK, so if this does turn out to be part of that plane...

GANYARD: Yes?

KARL: -- is it going to help us pinpoint where that plane went down?

GANYARD: Not really.

KARL: Or why?

GANYARD: Yes, not really, because they'll go back and they'll do some forensics on the metal. They'll look at how the metal twisted, how did it break. And it will tell us what -- what happened at the end when this airplane hits the water. But it's not going to tell us where those pieces of the airplane are thousands of miles back on the other side of the Indian Ocean, off the coast of Australia, where the real clues are, where the black boxes are and the real answers to this mystery are.

KARL: Thanks, Steve.

Now to that possible bombshell in the 2016 race -- is Joe Biden about to jump in?

ABC's Cecilia Vega with the new evidence the answer may be yes.

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CECILIA VEGA, ABC CORRESPONDENT (voice-over): This morning, the strongest signs yet that Joe Biden might be ready to run. The vice president's advisers telling ABC News his political team has been ramping up in recent days, entering what they call a more active phase.

JOE BIDEN, VICE PRESIDENT OF THE UNITED STATES: Hi, how are you?

VEGA: In Campaign Biden, there are discussions about fundraising and launching a political action committee. And while the vice president himself has not authorized any of these moves, one adviser tells ABC News he believes Biden is 90 percent in.

Biden telling George back in January that he is open to a run.

BIDEN: Yes, there's a chance. I don't think you have to make up your mind until the summer. I think there's a -- a -- I think this is wide open on both sides.