WASHINGTON (AP) — Vice President Joe Biden is urging the leader of Iraq's self-ruled northern Kurdish region to work with the governments of Iraq and Turkey to resolve a conflict over the region's oil.

Biden called President Massoud Barzani (mah-SOOD' bar-ZAH'-nee) on Thursday, the same day his Kurdish regional government announced it has unilaterally started sending crude to Turkey. Iraq's government and ethnic Kurds in northern Iraq are locked in a long-running dispute over oil rights.

The White House says Biden encouraged Barzani to talk with Baghdad to develop a way forward.

Biden has been working the phones this week as violence flares in Iraq two years after the U.S. pulled out troops. He's spoken twice with Iraqi Prime Minister Nouri al-Maliki (NOO'-ree ahl-MAHL'-ih-kee) and once with a leading Sunni lawmaker.