US lawmakers looked to have clinched a last-gasp deal to raise the country's debt limit and calm fears of a default after the Republican-controlled House of Representatives voted to pass the bill.

However, that did little to boost riskier assets, with Asian equities falling overnight as concerns about economic growth and the lingering threat of a US downgrade took over from fears of default and kept safe-haven government bonds in demand.

"OK, the US budget bill has gone through but there's plenty of speculation on the weakness of the economy there," a trader said.

"In this environment, Bunds are a buy on dips. Don't look at the yields, just go for the quality."

Bunds climbed to a high of 131.34 shortly after the open, up 17 ticks on the day.

On Monday, Bund futures climbed to their highest since last October after weak US manufacturing data fanned worries about the health of the world's largest economy, which will face fresh spending cuts under the debt ceiling agreement.

Worries in the euro zone also continued to support triple-A rated assets. Relief after policymakers agreed a plan to rescue Greece and enhance the region's rescue fund has given way to concerns about how the plans will be implemented.

With little on the calendar expected to bring clarity on that front, uncertainty remained high and supply out of Spain -- seen as one of the most fragile states that could need bailing out -- should keep peripheral euro zone debt under pressure.

Copyright Reuters, 2011