Pyongyang has protested the ongoing U.S.-South Korea military exercises, which are scheduled to wrap up at the end of the month.
In an effort to defuse tensions on the Korean peninsula, Park offered peace through dialogue Thursday, a surprise move that was welcomed by Kerry, who has repeatedly extended his support for bilateral talks, adding any missile launch would be a "huge mistake."
"I think she's shown great courage in her willingness to take [talks] in that direction, provided she has a willing partner," Kerry said in Tokyo.
Analysts have speculated that North Korea may launch a mid-range Musudan missile sometime before the April 15 celebration.
But on Sunday, South Korean local media questioned why the North's young leader Kim Jong-Un has not been seen in public over the past two weeks.
That's prompted further speculations, his absence may be a sign he "might be tempted to tone down fiery threats," though others say it may be a sign Kim is posturing for the launch.
His last public appearance was on April 1, at the annual rubber-stamp parliamentary meeting. Kim is widely expected to show up in the military parade in Pyongyang on Monday.