U.S. Secretary of State John Kerry has provided a much-needed boost to the Barack Obama administration's rebalancing toward Asia, as he wraps up a whistle-stop tour of three key regional countries.

Some questioned his role in the U.S. policy on Asia. He spent much of his time and energy in grappling with Syria, Iran and other Middle East issues over the first 10 months as Washington's top diplomat.

Throughout the five-day Asia swing, the Vietnam War veteran endeavored to show his commitment to the region, which is increasingly important for America's economy and global strategy.

"Secretary Kerry's fifth trip to Asia since taking office is further evidence of our commitment to the Asia rebalance and the great potential both on the economic and security front of the United States' relationship with Asia over the long term," the State Department's spokeswoman Jen Psaki, who's traveling with the secretary, told Yonhap News Agency.

Kerry especially chose South Korea as the first stop in his overseas trip this time.

His department has also allowed Yonhap to accompany Kerry on his special plane, making it the only non-Western news outlet in the traveling press.

It apparently reflects the secretary's focus on the South Korea-U.S. alliance amid North Korea's growing military threats.

In Beijing, the second leg of his trip, the secretary called on the Chinese government to do more to change the course of North Korea, given their unique ties.

Besides the North Korea issue, Kerry made a sales pitch for his signature campaign of combating climate change.

At the end of his two-day visit in Beijing, the two global powers issued a joint statement vowing to work together to address the issue.

He then flew to Jakarta, where he focused on climate change as well.

"Secretary Kerry had a productive and successful set of meetings with key leaders in the region from South Korea, China and Indonesia," Psaki said.

She added the secretary and his local partners "continued making progress on key issues, including coordinated efforts to prevent North Korea from making progress on a nuclear program, climate change and economic cooperation."

Kerry's Asia diplomacy has also laid the groundwork for Obama's renewed push for his Asia policy when he visits Japan, South Korea, Malaysia and the Philippines in April.

Critics accuse his administration of having lost steam in its strategic shift to Asia after a decade of wars in Iraq and Afghanistan.

Kerry, meanwhile, formerly a longtime politician who ran in the 2004 presidential election, sought to reach out to local residents.

He surprisingly toured a traditional market in Seoul, where he ate "tteokbokki," rice cake in red pepper paste.

In Beijing, he held a roundtable with a group of bloggers.

He started his official schedule in Jakarta by paying a 20-minute visit to the Istiqlal Mosque. He beat a gigantic drum at the largest mosque in Asia that is used to call people to prayer.

The question is how the secretary will maintain the momentum he gained from this Asia visit, with a host of urgent Middle East problems still unresolved.

Later Monday, the secretary heads to Abu Dhabi. (Yonhap)