A new website, a new presidential trip to the American heartland -- and still President Joe Biden is struggling to turn his successful bid to upgrade the United States' infrastructure into political capital.

Biden flew to Kansas City, Missouri on Wednesday on the latest stop of a tour he hopes will finally get Americans excited by the promise of transforming the roads, bridges and other vital links they use every day.

"Our 'Building a Better America' tour is going to give us a chance to meet people where they work... and showcase how our bipartisan infrastructure law, which has changed their lives for the better, came about," Biden said in a speech at the Kansas City transportation authority, which operates the mass transport.

"In the coming weeks, I'm going to be traveling all over the country. So will Vice President (Kamala) Harris, my cabinet, folks throughout my administration," he said.

In many ways, the recently passed infrastructure bill, budgeting $1 trillion for upgrading the nation's tattered transport networks, is a remarkable win.

Not only did the bill pass in Congress with support from a significant minority of Republicans, but the Democratic president managed to deliver something which both parties have talked about for years, without ever producing results.

Under Biden's predecessor Donald Trump, for example, broken promises of "infrastructure week" became a running joke.

US President Joe Biden speaks as he tours the Kansas City Area Transportation Authority in Missouri
US President Joe Biden speaks as he tours the Kansas City Area Transportation Authority in Missouri AFP / Nicholas Kamm

Yet for all that, Biden is not seeing a bounce in polling of the ordinary Americans he says the bill will help, with his approval rating bogged down in the low 40 percent area and Republican voters vehemently opposed to everything he does.

Biden has already made a string of similar speeches on factory floors or, in one chilly visit to New Hampshire, standing on an old bridge now set for much needed repairs.

Similarly, Biden's aides and even his wife, First Lady Jill Biden, have made multiple trips around the country, trying to put zest into the president's image.

"We're constantly looking for different avenues," White House spokeswoman Karine Jean-Pierre told reporters on Air Force One.

"We're constantly messaging, as you know, to the American people every day, making sure they know what it is that the president is doing to make their lives easier, to deliver for them," Jean-Pierre said.

The latest effort is a new website, build.gov, which was launched Wednesday as an effort to engage with regular Americans and even just explain to them what's in the giant spending package.

"Look, we're in a situation where we've known that our infrastructure had problems for a long, long time," Biden said in Kansas City.

Referring to the much ridiculed "infrastructure week" mantra, he said: "Guess what? It's going to be 'infrastructure decade.' No more talking. Action."