While just a few months ago Trump was hopeful for big wins on the international scene, has recently appeared frustrated on multiple fronts.
Tensions soar with Iran
Trump a year ago took the United States in a sharply different direction on Iran as he pulled out of a multinational deal negotiated under his predecessor, Barack Obama, under which Tehran drastically scaled back its nuclear work in return for promises of sanctions relief.
Trump instead has imposed an ever-mounting series of unilateral sanctions, including vowing to stop all countries from buying Iran's chief export of oil, as he seeks to curb the clerical regime's "destabilizing" role in the region.
But a year later, Iran has not met any of the 12 demands laid out by Secretary of State Mike Pompeo and European powers are openly dismissive of their US ally as they try to preserve the nuclear accord.
The showdown sharply escalated this month when the United States said it was deploying an aircraft carrier strike group and nuclear-capable bombers to the region in response to what officials called an imminent threat from Tehran.
But Trump ran for office on promises to scale back costly overseas interventions and a series of reports say he has begun to doubt the approach of his hawkish national security advisor, John Bolton, who for years has advocated attacking Iran.
Trump has said he wants dialogue with Iran -- which looks unlikely to reciprocate in a substantive way.
Impasse on North Korea
Unlike Iran, which still is observing the nuclear deal, North Korea has tested nuclear weapons -- and is estimated to be producing enough material for a new bomb every two months.
"This is a defeat. The end result of Trump will be that North Korea will continue to proliferate and Iran will return to proliferation," a European diplomat said.
North Korea was supposed to be the main success story for Trump, who held two landmark summits with leader Kim Jong Un in hopes of negotiating a deal to end its nuclear arsenal.
But the last encounter, in Hanoi in February, ended in stalemate with Trump's aides firm against lifting sanctions until North Korea comprehensively gives up its nuclear weapons.
Trump has voiced hope for reviving talks. But little headway is visible and North Korea recently tested two short-range missiles -- not seen as a violation of agreements, but still a sign of how much the situation has worsened.
Frustration in Venezuela
Trump had long criticized the US policy of regime change, advocated by neo-conservatives within his Republican Party in the 2000s. But the president himself has found an exception -- Venezuela.
In January, Trump declared President Nicolas Maduro -- a socialist who presides over a crumbling economy and whose re-election was tainted by widespread allegations of irregularities -- to be illegitimate and recognized opposition chief Juan Guaido as interim leader.
In a rare success at finding allies, more than 50 countries now back Guaido including most powers in Latin America and Europe.
But an April 30 uprising planned by Guaido quickly fizzled out, with the Trump administration saying several key figures in the Maduro regime failed to carry out promises.
Venezuela remains in a stalemate, with the United States refusing dialogue with Maduro. Guaido nonetheless said he sent delegates to Norway, which is seeking to mediate, although he denied talks with Maduro.
Power struggle intensifies with China
Trump as a candidate promised a tough line with China on trade and has carried through, recently slapping tariffs on a $200 billion tranche of Chinese merchandise and effectively barring telecom giant Huawei from the US market.
But a resolution on the trade disputes between the world's two largest economies remains elusive, despite rounds of talks and several indications that an accord was imminent.
China has announced its own retaliatory tariffs and has struck back, in particular by drastically cutting purchases from US farmers and ranchers -- a crucial voting base for Trump in next year's election.
Syria, Afghanistan withdrawal
Trump took office vowing to end seemingly perpetual wars that have brought enormous costs to the United States over the past two decades.
But his promise in December to withdraw all of the estimated 2,000 US troops in Syria triggered a backlash that contributed to the resignation of his respected defense secretary, Jim Mattis.
Trump has since walked back the promise, with US officials saying that the United States will keep a small force in Syria.
On Afghanistan, where the United States has been at war for nearly 18 years, veteran diplomat Zalmay Khalilzad has entered talks with the Taliban and both sides have voiced optimism for future rounds.
But the Taliban refuse to speak to the government in Kabul and have not given up on violence, earlier this month killing nine people in an attack on a US-funded non-profit group.