Corruption is a “cancer” that blocks opportunities for African nations seeking international investment, Vice President Biden said Monday, as the Obama administration welcomed African leaders for talks aimed at broadening American business relationships on the continent.

“Widespread corruption is an affront to the dignity of your people and a direct threat to each of your nations,” Biden said. “It stifles economic growth and scares away investment and siphons off resources that should be used to lift people out of poverty.”

That’s a familiar lecture from Western governments, but the Obama administration hopes the message resonates differently during the business-oriented gathering in Washington.

The summit is the largest of its kind organized by the United States but comes years after a similar trade and investment recruitment conference hosted by China.

China has been Africa’s largest trading partner since 2009, with billions invested in mining, infrastructure and construction.

Speaking to an audience of African activists and nonprofit organizations, Biden said African nations seeking to break the yoke of endemic or official corruption need impartial courts, security services and police “beholden to no one but the people,” and auditors free to “look at the books” without fear of retaliation.

Transparency International rates all countries in Africa as moderately to highly afflicted with official corruption. Botswana got the nonprofit organization’s highest rating for the continent last year, with a score of 64 out of a possible 100. Somalia scored the worst among African nations, with 8 points out of 100.

“We want and we will work hard to get more American companies to invest in Africa,” Secretary of State John F. Kerry said Monday. “We also want more African companies to invest here in the United States, and there’s no reason that they shouldn’t.”

Kerry also made a business argument for confronting corruption.

“Transparency and accountability attract greater investment,” Kerry said. “Transparency and accountability create a more competitive marketplace, one where ideas and products are judged by the market and by their merits, and not by a backroom deal or a bribe.”