The two leaders were to meet in Belfast on Cowen's first full day on the job to review political progress in Northern Ireland and discuss strategic European and global issues, Ireland Online reported.
"I am delighted that on my first full day in office, I will be meeting with ... Brown, First Minister (Ian) Paisley and Deputy First Minister (Martin) McGuinness," Cowen said. "Today's meetings and investment conference are a mark of the huge progress we have made in recent years and a clear signpost to the better future that we are together building for everyone on the island of Ireland."
Cowen, who had been finance minister, replaced Bertie Ahern, who resigned after holding the post for 11 years. Ahern was undermined by allegations of financial irregularities, which he has consistently denied.