Wang is also arbitration-eligible after the 2010 season, so the Nationals will have control of his future.
The team signed Wang on the recommendation of several scouts, including Phil Rizzo, Ron Schueler and Jay Robertson, who scouted Wang while he was working out in Arizona.
"This is a great new opportunity and a new start," Wang said through interpreter Alan Chang. "I would like to do my best to make a contribution to this team's tradition."
The news conference took place on the Space Coast Stadium field. There were at least 40 media members in attendance and the media room inside the stadium was too small to hold the contingent.
Teammates such as pitchers Matt Capps, Tyler Clippard, John Lannan and Collin Balester were all in attendance, and Balester gave up his uniform number, 40, to Wang. Balester will now wear No. 99. Representatives from China and dignitaries from Taiwan were also at the Wang's news conference.
The Nationals believe acquiring Wang, 29, was worth the risk even though he will not be ready for Opening Day. He is still recovering from arthroscopic surgery on his right shoulder. Wang is still throwing on flat ground from 120 feet.
Wang is expected to go back to Arizona on Friday to work out and then rejoin the team in Florida on March 7. He will continue baseball activities the next day.
Washington is hoping that Wang will be able to pitch in a big league game by May.
"We thought at 29 years old, we have a pitcher who could not only help us in the short term, but help us in the future," general manager Mike Rizzo said. "Obviously, we did our due diligence on the medical side. He has been seen by our team physicians, Dr. James Andrews and several others.
"We are confident that his shoulder is going to bounce back, and he will pitch pain free and injury free. If that's the case, then we feel we have ourselves a front-of-the-rotation starter who has proven it on the biggest stage in baseball."
Over the past two seasons, Wang has pitched in a combined 27 games. In 2008, he didn't pitch after the All-Star break because of foot problems, and this past season, he missed the Yankees' World Series run because of his shoulder.
Wang has shown that, at his best, he can be the ace of a pitching staff. In 2006 and '07, he went a combined 38-13 with a 3.67 ERA for the Yankees. Wang is known for his tremendous sinker.
"I look forward to becoming the sinker-ball pitcher that I was prior to the surgery," Wang said. "I'm also looking to develop some new pitches -- give the hitters a different look. ... I'm very comfortable with [my new teammates]. I'm looking forward to knowing them, playing together and winning a championship.
"My No. 1 goal is returning as one of the best pitchers in Major League Baseball. I will do everything possible to make myself stronger again and give myself every possible way to be one of the best starting pitchers in the league."
Manager Jim Riggleman can't wait for Wang to be a major contributor for the Nationals. Riggleman believes there is no rush to put Wang on the field.
"I feel real good about it on a lot of levels," Riggleman said. "The acquisition of Wang allows us to take our time with him. ... With the experience that Craig Stammen, J.D. Martin and Garrett Mock had last year, it allows us not to rush [Wang]. We'll let him come back at the pace that he needs to come back. And then when he comes back, hopefully, he is 100 percent. It's going to feel like a heck of a trade, except we didn't lose anybody."
After Wang was non-tendered by the Yankees on Dec. 12 of last year, the Nationals immediately called agent Alan Nero to inform him that they had serious interest in Wang. Nero said at least 15 teams showed interest, but Washington was the most aggressive in trying to acquire his services.
The Nationals' biggest competitor was the Dodgers, but "... in the end, the Dodgers were behind," Nero said. "In the end, we ended up with three offers, but the Nationals were the most sincere, they were the most aggressive, they were ahead of the pact and they did all of their due diligence. They were confident along the way.
"They didn't act like they were concerned or use the leverage of, 'Well, we don't know if he is going to be OK.' Anytime you make a decision like this, the spirit of it matters. It's kind of like dating. You don't enter into a relationship if you don't feel real good about it."
The Nationals are hoping that the signing of Wang can help them get more players from Asia.
"This is our first endeavor into the Pacific Rim market," said Rizzo. "To have our first player from Asia to be the Michael Jordan of Taiwan is an important day for the Washington Nationals."
In the order to put Wang on the 40-man roster, the Nationals placed right-hander Jordan Zimmermann on the 60-day disabled list. Zimmermann is still recovering from Tommy John surgery. He is not expected back until sometime in August.
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.