A statement from Ashton's office yesterday said she reaffirmed support for Palestinian state-building and the need for Palestinians to reconcile "as an important element for the unity of a future Palestinian state and for reaching a two-state solution."
The Islamist Hamas movement and its rival Fatah, Abbas's party that dominates the West Bank-based Palestinian Authority, have been at odds since Hamas's takeover of the Gaza Strip in 2007.
Since signing an Egyptian-brokered deal in 2011 they have been attempting to heal their rifts.
But the implementation of the accords has stalled over the make-up of the interim government, and a February 2012 deal intended to overcome differences was opposed by Hamas members in Gaza.
Also Read
During talks with EU leaders on Wednesday, Abbas urged European and other foreign companies not to deal with businesses based in Jewish settlements.
Abbas said a boycott would not be aimed at the state of Israel but only targeted at Jewish settlements on occupied Palestinian land in the West Bank and east Jerusalem.
Several European retail giants also import produce from the West Bank, which is home to large farms producing fruit, vegetable and flowers.