Clayton Lockett, seen here in a June 29, 2011, file photo, died April 29, 2014, from a heart attack following a botched execution attempt. (Oklahoma Department of Corrections/AP Photo)

Oklahoma's botched lethal injection was "deeply troubling," President Obama said today when asked by a German reporter about America being in the company of human-rights violators such as China when it comes to using the death penalty.

Obama fielded the question during a joint press conference with German Chancellor Angela Merkel in the White House Rose Garden. Merkel visited to meet with Obama amid swiftly escalating conflict in eastern Ukraine.

The president said he will discuss the matter of Oklahoma's botched execution with Attorney General Eric Holder.

"What happened in Oklahoma is deeply troubling," Obama said, noting that he nevertheless supports the death penalty when "heinous" crimes are committed.

"I'll be discussing with Eric Holder and others, you know, to get me an analysis of what steps have been taking, not just in this particular instance, but more broadly in this area," Obama said.

Related: New Timeline Suggests Missteps in Botched Oklahoma Execution

Obama noted racial disparities in executions and instances of death-row inmates proven innocent after exculpatory evidence was uncovered.

Death row inmate Clayton Lockett, 38, died of a heart attack more than 40 minutes after an attempted lethal injection on Tuesday left him writhing on a gurney but did not immediately kill him.