TEHRAN, July 14 (Xinhua) -- Iran is ready to hold negotiations with the United States if Washington lifts sanctions against Tehran, Iranian President Hassan Rouhani said on Sunday.

"We are always ready for negotiation. I tell you this hour and this moment to abandon bullying and lift the sanctions and return to logic and wisdom. We are ready," the Iranian Mehr News Agency quoted Rouhani as saying.

Leaders of France, Germany and Britain, European signatories of the 2015 Iran nuclear agreement said on Sunday they are "extremely concerned" about the escalating tension in the Gulf region, which they said is likely to put the accord at risk unless the concerned parties join the same table of talks.

In May last year, Washington unilaterally abandoned the Iran nuclear deal and restarted to sanction Iran. On May 8, Iran stopped implementing some of its commitments under the deal and set a 60-day deadline for the Europeans to help Iran reap the economic benefits of the deal.

On July 7, as the deadline expired, Iranian Deputy Foreign Minister Seyed Abbas Araghchi announced that Iran was ready to begin enriching uranium beyond the 3.67-percent level set in the Iran nuclear deal, adding that Tehran would go on gradually abandoning its nuclear commitments every 60 days.

On July 8, Iran announced that it had raised the concentration of its enriched uranium to 4.5 percent from 3.67 purity.

Following Tehran's announcement, U.S. Vice President Mike Pence, along with other senior Trump administration officials, vowed to continue to pile up economic pressure on Iran.