It was not clear what prompted Thursday's tweet by Trump, who takes office on January 20, but it came the same day Russian President Vladimir Putin said his country needed to boost its nuclear forces.
In his yearend news conference in Moscow on Friday, Putin said Trump's comment on Wednesday was not out of line and that he did not consider the United States to be a potential aggressor, Reuters reported.
Trump Spokesman Sean Spicer said in several television interviews on Friday that there would not be an arms race because the president-elect would ensure that other countries trying to step up their nuclear capabilities, such as Russia and China, would decide not to do so. "He's going to ensure that other countries get the message that he's not going to sit back and allow that," Spicer, who was named this week as White House spokesman for the president-elect, told NBC.
