A day after urging Republicans to refrain from criticizing the nation’s leader while he is overseas, House Speaker John Boehner (R-Ohio) demanded Wednesday that President Obama clarify remarks he made to his Russian counterpart that drew partisan concern at home.

In a letter to the president made public Wednesday afternoon, Boehner wrote that he was “alarmed” after learning that Obama told Russian President Dmitry Medvedev that he needed “space” during his re-election campaign. Obama said he would have more “flexibility” to address Russia’s concerns over the missile-defense system that the United States is putting in place in Eastern Europe, among other issues, if he wins a second term.

Obama made those comments during a private sideline conversation at a summit in Seoul, South Korea, but his words were captured on an open microphone. Obama asked Medvedev to convey his message to incoming President Vladimir Putin, who is returning to the Kremlin after an election earlier this month that international observers characterized as neither free nor fair.

Republican front-runner Mitt Romney seized on those remarks to suggest that Obama intends “to cave to Russia on missile defense,” an allegation the White House has denied. Romney added that “the American people have a right to know where else he plans to be ‘flexible” in a second term.”

At the time, Boehner chided the likely Republican presidential nominee, saying that “while the president is overseas I think it’s appropriate that people not be critical of him or our country.” With Obama back in town, though, Boehner made public his own concern over the exchange.

“It is troubling that you would suggest to Russian leaders that their reckless ambition would be rewarded with greater ‘flexibility’ on our missile defense program after the upcoming election,” Boehner wrote. “That has significant implications for the security of our homeland, sends a terrible signal to our allies around the world, and calls into question the effectiveness of your ‘reset’ policy with the Russian government.”

Boehner concluded by saying that “a post-election surprise on this critical issue would not be welcomed by the American people, the Congress, or the world community.”

“I look forward to your response,” he wrote.