A few days after Rubio challenged Obama's domestic agenda in the official Republican rebuttal to the president's State of the Union address, the junior senator from Florida criticized Obama on foreign policy.

Rubio, who has been regularly mentioned as a possible presidential candidate in 2016, wrote in a Foreign Policy piece published Friday that the president has been standing "idly by" as turmoil spreads across the Middle East and countries like North Korea and Iran continue to advance their nuclear programs. Rubio urged further action in Syria, greater transparency in Afghanistan and new sanctions in response to North Korea’s recent nuclear test.

"The biggest foreign policy problem facing the United States right now is not too much U.S. engagement, but the danger of a world in which we increasingly refuse to lead," Rubio writes. "There are few global challenges that can be solved without decisive American leadership. …The president's policies have often, in effect, been to just ignore many of these problems."

Rubio also tied his foreign policy criticism of Obama to the national debt and the economy. He wrote that the government’s failure to get its fiscal house in order has given our allies "cause to question our staying power and commitment to their security and our shared ideals."

Rubio condemned Obama’s plan for raising taxes to offset looming automatic cuts to defense and discretionary spending scheduled to go into effect March 1. He urged the president to embrace House Republicans' approach to dealing with the cuts.

"Fulfilling the promise of America will only be possible if we embrace, not continue to run away from, the essential role that our country has played in contributing to global stability," Rubio wrote. "That will require assertive leadership both home and abroad. It’s time to take up the challenge."