BERLIN, April 19 (Xinhua) -- German Chancellor Angela Merkel expressed concern over Iran's ballistic missile program at the sidelines of a meeting with French President Emmanuel Macron here on Thursday.

Speaking ahead of a scheduled trip to Washington, Merkel said the European Union (EU) was still keen to uphold the Iranian nuclear dis-armament treaty despite President Donald Trump's decision to withdraw support from the multilateral accord. At the same time, however, the chancellor told press that not all issues with Tehran could be "reduced to the (nuclear) treaty", and described the country's ballistic missile program as a "source of concern".

Similarly, Macron said that Western relations with Iran could not just be defined on the basis of the nuclear treaty. Both Macron and Merkel intend to hold urgent consultations with Trump, who has threatened to proceed with a U.S. de-ratification of the treaty as early as May in an attempt to renegotiate its content.

Germany, France and Britain have all warned Washington from taking such a radical step. The three European powers are worried that a U.S. departure could lead to an escalation of regional conflict in the Middle East.

Trump has demanded the nuclear deal be altered to eliminate sunset clauses for some of the restrictions it places on Iran, and harden the inspection rules and to limit development of Iran's long-range missiles.

Iranian President Hassan Rouhani has warned against probable pullout of the United States from the 2015 landmark nuclear deal, saying that "If the deal collapses, they will surely regret it."

So far, assessments by the International Atomic Energy Agency (IAEA) indicate that Iran is complying fully with the conditions set out in the nuclear accord.