|North Korean leader Kim Jong Un waves to people cheering during an opening ceremony of a newly constructed residential complex in Ryomyong street in Pyongyang, North Korea April 13, 2017. REUTERS/Damir Sagolj
Concern has grown since the U.S. Navy fired 59 Tomahawk missiles at a Syrian airfield last week in response to a deadly gas attack, raising questions about U.S. President Donald Trump's plans for North Korea, which has conducted missile and nuclear tests in defiance of U.N. and unilateral sanctions.
The United States has warned that a policy of "strategic patience" is over. U.S. Vice President Mike Pence travels to South Korea on Sunday on a long-planned 10-day trip to Asia.
China, North Korea's sole major ally and neighbor which nevertheless opposes its weapons program, has called for talks leading to the denuclearization of the Korean peninsula.
"We call on all parties to refrain from provoking and threatening each other, whether in words or actions, and not let the situation get to an irreversible and unmanageable stage," Chinese Foreign Minister Wang Yi told reporters in Beijing.
North Korea denounced the United States for bringing "huge nuclear strategic assets" to the region as the Carl Vinson strike group with a flag-ship nuclear-powered aircraft carrier steamed closer, and said it stood ready to strike back.
"The Trump administration, which made a surprise guided cruise-missile strike on Syria on April 6, has entered the path of open threat and blackmail," the North's KCNA news agency quoted the military as saying in a statement.
"The army and people of the DPRK will as ever courageously counter those who encroach upon the dignity and sovereignty of the DPRK and will always mercilessly ravage all provocative options of the U.S. with Korean-style toughest counteraction."
DPRK stands for the North's official name, the Democratic People's Republic of Korea.
North Korea, still technically at war with the South after their 1950-53 conflict ended in a truce, not a treaty, has on occasion conducted missile or nuclear tests to coincide with big political events and often threatens the United States, South Korea and Japan.
On Saturday, it marks the "Day of the Sun", the 105th anniversary of the birth of state founder Kim Il Sung.
U.S. ally South Korea warned against any North Korean "provocation", such as a nuclear or missile test.
"There is certain to be powerful punitive measure that will be difficult for the North Korean regime to endure," the South's Foreign Ministry said in a statement.Reuters