President Trump’s message to the United Nations Monday was to focus on reform and to work to reach the organization’s “full potential,” he said in an opening session ahead of his inaugural address at the General Assembly later this week.

The President, who has been sharply critical of the U.N. in the past and previously called to defund the organization, appeared to strike a more conciliatory tone urging “member states to look at ways to take bold stands at the United Nations with an eye toward changing business as usual and not being beholden to ways of the past which were not working.”

In his opening remarks, he also praised U.S. Ambassador to the U.N. Nikki Haley and new Secretary General António Guterres, who campaigned on a platform of reform, telling those assembled that the U.S. was looking to “partner” in their work.

“Make the United Nations great. Not again. Make the United Nations great,” the President said to reporters Monday, borrowing from his election slogan and delivering mild criticism of the organization’s bureaucracy and mismanagement.

With a campaign fought under a banner of “America first,” there has been much focus on signs of cooperation between the Trump administration and the U.N.

Last month, Trump applauded a U.N. vote to impose new sanctions on North Korea following repeated nuclear capable missile tests in recent months. Several Trump critics offered cautious words of praise for the President noting the likes of Russia and China voting in favor of sanctions.

Trump is also meeting with world leaders on the sidelines of the summit, where he is expected to address regional matters including Syria and Iraq post-ISIS, the global war on terrorism and the status of the nuclear deal between Iran and world powers.

Prompted by reporters Monday as he met with Israel’s Prime Minister Benjamin Netanyahu, Trump said the world will “see very soon” whether the U.S. will remain committed to the nuclear agreement with Iran. Previously, during his campaign, the President called the deal “one of the worst deals the U.S. has participated in.”

Trump’s Ambassador to the U.N. Haley has hinted the U.S. may opt against recertification next month when the White House faces a deadline to inform Congress of its intentions.

Of concern to the President and Prime Minister Netanyahu are Iran’s pursuance in underwriting terror sponsorship across the region as well as Tehran’s emergence as a key player in the Syria conflict—of particular concern to Israel.

In an interview Sunday with CBS’s Face the Nation, Secretary of State Tillerson said that since the nuclear deal was signed, Iran has “stepped up its destabilizing activities” in Yemen and Syria and “exports arms to Hezbollah and other terrorist groups and continues to conduct a very active ballistic missile program.”

Trump is also meeting with leaders from Latin America where he’s expected to address the political unrest in Venezuela. Violent anti-government demonstrations and the inauguration of a new constitutional assembly deemed authoritarian, prompted the U.S. to levy new sanctions against the Latin American oil-rich country.