At the G-20 summit, the US, Japan, and South Korea are attempting to win backing for a Security Council resolution against North Korea.
The US has said it won't use destroyers to shoot missiles down. But they could gather intelligence.
The missile launch is believed to be a military test, though Pyongyang insists it is launching a satellite.
Did the two women cross into North Korea, or did border guards lure them over?
The move comes as South Korea and the US begin a large-scale joint military exercise.
In South Korea, which she visited Thursday, fears persist that the US will move forward on ties even if the North resists verifying disablement of its weapons.
She'll talk with China and three other nations about climate change, the financial crisis, and more.
Recent moves to possibly test a long-range missile may be aimed at grabbing US attention.
Excessive congressional clapping rivals contrived Soviet outbursts.