Secretary of Defense James Mattis issued a stark warning to North Korea on Friday: the U.S. will respond with "overwhelming" force in retaliation to any attack against America or its allies.

"Any attack on the United States, or our allies, will be defeated, and any use of nuclear weapons would be met with a response that would be effective and overwhelming," Mattis said at the South Korean defense ministry.

The defense secretary told officials in Seoul that American commitment is "ironclad" and, speaking later in Tokyo with Japanese Prime Minister Shinzo Abe, said the U.S. stands "100 percent shoulder to shoulder with you and the Japanese people."

Abe is scheduled to meet with President Donald Trump in Washington on Feb. 10. White House press secretary Sean Spicer said Friday that national security and trade would be the main topics discussed, without elaborating further. The president last met with the prime minister in New York shortly after winning the election in November . According to a White House readout, Trump likewise promised Abe an "ironclad U.S. commitment to ensuring the security of Japan" in a Jan. 28 phone call.