U.S. stocks swung sharply as uncertainty about what will happen in the war with Iran increased.

The S&P 500 fell as much as 1.2% Tuesday, hours ahead ahead of a deadline by President Donald Trump to destroy Iranian power plants and bridges.

Stocks rallied back in late trading after Pakistan’s prime minister urged Trump to extend his deadline for another two weeks and asked Iran to open up the Strait of Hormuz for two weeks.

The S&P 500 erased all its losses and ended 0.1% higher. The Dow Jones Industrial Average slipped 0.2%, and the Nasdaq composite edged up 0.1%.

On Tuesday:

The S&P 500 rose 5.02 points, or 0.1%, to 6,616.85.

The Dow Jones Industrial Average fell 85.42 points, or 0.2%, to 46,584.46.

The Nasdaq composite rose 21.51 points, or 0.1%, to 22,017.85.

The Russell 2000 index of smaller companies rose 4.30 points, or 0.2% to 2,544.94.

For the week:

The S&P 500 is up 34.16 points, or 0.5%.

The Dow is up 79.79 points, or 0.2%.

The Nasdaq is up 138.67 points, or 0.6%.

The Russell 2000 is up 14.90 points, or 0.6%.

For the year:

The S&P 500 is down 228.65 points, or 3.3%.

The Dow is down 1,478.83 points, or 3.1%.

The Nasdaq is down 1,224.14 points, or 5.3%.

The Russell 2000 is up 63.04 points, or 2.5%.