U.S. stocks closed sharply lower on Tuesday as renewed concerns over the Greek debt crisis sent Wall Street the worst day so far in 2012.

The Dow Jones industrial average lost 203.66 points, or 1.57 percent, logging its first triple-digit decline in 2012, to close at 12,759.15. The Standard & Poor's 500 was down 20.97 points, or 1.54 percent, to 1,343.36. The Nasdaq Composite Index dropped 40. 16 points, or 1.36 percent, to 2,910.32.

A new round of concerns about the Greek debt crisis began from last Friday, when rating agency Moody's downgraded Greece credit rating to "C" from "Ca", becoming the third rating agency to cut the country's credit rating.

A debt swap deal between the Greek government and private creditors plays an important role in a second bailout loan for the Greece that aims to avoid defaulting. However, investors were concerned that some of its creditors would oppose the deal which would incur a chaotic default.

Meanwhile, senior Greek finance ministry officials said the debt swap deal will be completed on time. The deadline is Thursday.

The CBOE Volatility Index, which is widely regarded as the best gauge of fear in the market, jumped above 20 for the first time since mid-February. All 10 S&P sectors were firmly in negative territory, led by financials and industrials.

The technology sector also fell on Tuesday. Apple edged lower even Barclays raised its target price 710 dollars per share from 630 dollars per share. Google and Yahoo also dropped.

Also, the political tensions between Iran and Israel caught investors' attention. U.S. President Barack Obama on Tuesday also said he was concerned about oil output around the world as gasoline prices soared. Oil price dropped on Tuesday on Greece concern, after spiking for weeks.

In other markets, the euro also tumbled as investors lost confidence on the shared currency, while the dollar surged, lifted by risk-aversion appetite. Gold price lost nearly 2 percent on a stronger dollar.