U.S. President Donald Trump heads into the 2020 election year claiming credit for a strong economy and trade victories over China and Japan that he says will significantly benefit American manufacturers and farmers.

On the diplomatic front, however, one of Trump's biggest ambitions -- to rid North Korea of its nuclear weapons -- is facing a major test as Pyongyang increases its provocations again amid the stalled denuclearization talks.

While Trump made history in June last year by becoming the first sitting U.S. president to meet a North Korean leader, little progress has been seen toward persuading the long-term adversary to give up its nuclear arsenal.

Trump has asserted that "peace" has been maintained, citing the pause in North Korea's long-range ballistic missile and nuclear tests as one of the accomplishments of his three face-to-face meetings with Kim Jong Un.

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But North Korea has apparently continued to hone its weapons technologies through the test-firing of short-range ballistic missiles -- tests that Trump has downplayed.

It has also stepped up its provocative rhetoric to wring concessions from the United States ahead of a year-end deadline it has set for progress in the denuclearization talks, sparking concerns that it may be close to restarting the testing of intercontinental ballistic missiles. Such missiles would pose a threat to the U.S. homeland.

Some experts on East Asian security issues said Trump is not inclined to go back to the situation seen in 2017, when North Korea's nuclear and missile threats led him to warn of raining "fire and fury" down on Pyongyang and the possibility of military conflict.

But the Trump administration needs to tread carefully with regard to North Korea, as any bold bets could backfire with only 11 months left before the presidential election.

"I think they (the United States) will take a relatively restrained approach" if North Korea tests an ICBM for the first time since November 2017, James Schoff, a senior fellow at the Carnegie Endowment for International Peace, said.

"What they would do would probably be to press for tougher sanctions enforcement and look for ways in the cyber realm in particular to apply pressure on North Korea, because North Korea has really been using the cyber realm, cybercrime and other ways to try to raise money," he added.

Trump has so far expressed hope that North Korea will exercise restraint, suggesting that he has faith in Kim, whom he has touted as having a "very good relationship" with.

"He knows I have an election coming up. I don't think he wants to interfere with that," Trump said in early December.

For Trump, making easy concessions, such as offering significant sanctions relief in exchange for partial North Korean disarmament steps, could draw criticism that he simply rushed to make a deal.

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Tobias Harris, a Japan expert at consulting firm Teneo, said that handling North Korean provocations will be "really challenging" for the United States at a time when Trump has been putting pressure on key allies Japan and South Korea with suggestions they are free-riders on security.

Although trilateral cooperation is essential in countering threats from North Korea, the Trump administration has demanded that South Korea significantly increase its contributions for stationing U.S. troops in the country and is likely to make similar requests once negotiations on host-nation support start with Japan next year.

The leaders of the House of Representatives committees on foreign affairs and armed services, both Democrats, have expressed concerns that such requests could raise questions about the U.S. commitment to the region.

But Harris said Trump apparently believes that the allies need to "pay up" -- an argument which has not changed since his campaign for the previous 2016 election -- and that such behavior could characterize his second term if he is re-elected.

"The administration is now full of people whose loyalty is to Trump and not...people who maybe were committed to more of a bipartisan consensus. In a second term, I think that would be even more of the case. So the real test might come after the election next year depending on who wins," the Washington-based analyst said.

As for the Democratic Party, the field of presidential hopefuls seeking their party's nomination is still crowded and it is unclear who will take on the fight against Republican Trump, 73, in the election on Nov. 3.

The first nominating contest for the Democratic Party's presidential candidate will be held on Feb. 3 in the Midwest state of Iowa to be followed by Super Tuesday, when many states will hold presidential primaries, on March 3.

According to a major poll tracking website, former Vice President Joe Biden, 77, holds a lead over his two nearest rivals -- 78-year-old Bernie Sanders and 70-year-old Elizabeth Warren, both left-wing senators.

Pete Buttigieg, a 37-year-old Midwestern mayor who is also an Afghanistan war veteran and gay, is garnering attention among voters seeking a fresh face with moderate policy positions.

[Getty/Kyodo: 3rd from L to R, Elizabeth Warren, Joe Biden and Bernie Sanders]

During a series of Democratic presidential candidate debates earlier this year, the focus has largely been on domestic issues such as health care programs and Trump's impeachment by the House over his dealings with Ukraine.

While details of each contender's foreign policy in Asia have yet to come under scrutiny, Harris pointed to some uncertainties that a Democratic administration may bring, citing as an example pledges made by Warren to cut defense spending.

"Even someone like Warren, with some relatively mainstream foreign policy views...wants to reduce defense spending, so what does that mean for U.S. security guarantees (to countries like Japan)?" the expert said.

A Japanese government source said it is difficult to predict the outcome of the U.S. presidential election now, but added, "We will just try to be prepared for whoever will be elected."