Republican presidential candidate Marco Rubio talks at a forum in Columbia, S.C., on Saturday. (Sean Rayford/AP)

Sen. Marco Rubio (R-Fla.), who has come under heavy criticism from his Republican presidential rivals for his absences from the Senate, scrapped plans to appear at a Florida fundraiser on Monday so he could fly back to Washington to attend a 5 p.m. classified briefing on North Korea, his campaign said.

Rubio adjusted his plans to appear at a closed-door Senate Foreign Relations Committee hearing titled "Assessing the Recent North Korea Nuclear Event." Officials from the State Department, the Office of the Director of National Intelligence and the Defense Department were scheduled to appear at the briefing.

The Florida Republican held an economic policy town hall in Sarasota, Fla., on Monday afternoon. He had been scheduled to attend a 6 p.m. fundraiser at a golf club on Key Largo, which critics pointed out in advance of the briefing.

"Marco has routinely left the campaign trail for important briefings and votes in Washington. He returned to Washington for an Intelligence briefing following the Paris attacks and is coming to DC for the classified Foreign Committee hearing on North Korea today. No other Republican running for president has received as many classified intelligence briefings as Marco, and nobody better understands the threats facing America in the 21st Century," Rubio campaign spokesman Alex Conant said in an emailed statement. Conant did not immediately respond to a question about whether Rubio arrived in time for the start of the briefing.

Rubio has shown a lot of interest in North Korea as a candidate for president. He routinely calls North Korean leader Kim Jong Un a "lunatic," and after reports about an alleged hydrogen bomb test last week, he quickly issued a statement: "If this test is confirmed, it will be just the latest example of the failed Obama-Clinton foreign policy."

study by Vocativ and Govtrack last fall found Rubio to be the most absent member of the Senate. His opponents have slammed him for missing votes. He has also faced questions from voters on the campaign trail.

"The truant officer is out looking for him," New Jersey Gov. Chris Christie (R) said of Rubio in an interview broadcast Monday morning on MSNBC.

Rubio will be in Washington on Tuesday for President Obama's final State of the Union address. He is also slated to hold a fundraiser in the city earlier in the day. More than two dozen members of Congress are scheduled to attend.