Westerwelle wants to spend more time on his "domestic political responsibilities" in the new year, according to Sunday newspaper Welt am Sonntag.
Having brought the FDP to power on the back of a host of promises for domestic reform - in areas from tax to healthcare, social welfare, and licence fees - Westerwelle is keen to show voters that he has not abandoned these ambitions despite his new role in international politics.
Some critics have since raised doubts about the seriousness of his politics, after he was so eager to take on the role of foreign minister - traditionally the position of the leader of the junior coalition partner - when his campaign agenda was so resolutely domestic.
But Westerwelle promised that people in his home state of North Rhine-Westphalia, where a vital election will be held next May, will see him on the campaign trail – "in the marketplaces and halls, as always".
The election in Germany's most populous state is vital as a mid-term political barometer but could also tip power against the ruling coalition government of Christian Democrats and FDP in Germany's upper parliamentary house, the Bundesrat. Westerwelle told the newspaper he wants to "make sure that communists and socialists don't get political influence on my home ground."
Westerwelle also admitted to certain insecurities in his new job. "It was a completely new experience for me to suddenly be walking on red carpets in the capitals of the world," he said.
"Of course you don't want to make any mistakes when you're inspecting a guard of honour for the first time. I wasn't born into being greeted by the French president. I grew up in a middle class home in Bonn. Why should I pretend I just breezed through it?"
Westerwelle described the first weeks of being foreign minister as "draining", but said they were among the most exciting of his life.