WASHINGTON - President Barack Obama's planned meeting with his Philippine counterpart was canceled because the tone of the Philippine leader's rhetoric raised questions about the chances for a productive talks, the U.S. State Department said on Tuesday.

READ: Duterte calls Obama a 'son of a w****'

"Words matter, and we want to see an atmosphere that is cordial and open to strong cooperation," State Department spokesman Mark Toner said.

President Rodrigo Duterte hurled expletives while discussing a scheduled meeting with Obama, emphasizing that he would not be lectured over extrajudicial killings in the Philippines' drug war.

Duterte later voiced regret for his language. The two had been scheduled to meet on the sidelines of the ASEAN summit in Laos.

READ: Duterte 'regrets' comments vs. Obama, hopes to resolve spat

The White House cancelled the two leaders' bilateral meeting on the sidelines of the ASEAN Summit but Malacanang said the cancellation was a mutual decision.

The firebrand said he hopes to resolve his spat with Washington, a long-time ally of the Philippines.

"Our primary intention is to chart an independent foreign policy while promoting closer ties with all nations, especially the US with which we have a had long standing partnership," Duterte said.

"We look forward to ironing out differences arising out of national priorities and perceptions, and working in mutually responsible ways for both countries."