A worker at the t-shirt store of Truong Thanh Duc dry the newly printed t-shirts with the portraits of U.S. President Donald Trump and North Korean leader Kim Jong Un on February 21, 2019 in Hanoi, Vietnam. Linh Pham | Getty Images

U.S. President Donald Trump and North Korean leader Kim Jong Un are meeting in Vietnam this week for the second time in less than a year, in a bid to get Pyongyang to give up its nuclear program in exchange for sanctions relief. But experts say they don't have high expectations from this week's meeting, set to take place in Hanoi on Wednesday and Thursday. Washington has demanded that Pyongyang abandon all its nuclear and missile programs, while North Korea wants crippling sanctions to be removed as part of denuclearization negotiations. "So far, North Korea seems only willing to take measures that limit its nuclear and missile capabilities, it has no indications that it wants to roll back or undercut its existing nuclear arsenal or missile arsenal," Tong Zhao, a fellow at the Carnegie-Tsinghua Center for Global Policy, told CNBC on Tuesday. However, the meeting will be timely for the two sides to negotiate some meaningful progress so that Pyongyang is held back from taking "risky and destabilizing nuclear postures," said Zhao. Measures that could yield some results include capping further development of nuclear weapons, he told CNBC. "The only way that North Korea can be reassured about its own security is for the U.S.-(North Korea) bilateral relationship to be fundamentally transformed from a hostile one to a friendly one," said Zhao.

Denuclearization

Following their historic meeting in Singapore last June, key issues remain: The denuclearization of the Korean Peninsula, as well as sanctions on Pyongyang which have taken a toll on the North's economy. "I don't think the two sides are close at all in terms of what they mean by denuclearization," said Zachary Abuza, a Professor at the National War College. He added that U.S. intelligence has shown that Pyongyang continued its development of nuclear arms and the systems to deliver those weapons after their last meeting. North Korea conducted its last nuclear test in September 2017 and last tested an intercontinental ballistic missile in November 2017. "For any arms control to really work effectively, we have to have a full inventory of what they have, their different labs and it's very hard to see the North Koreans actually coming clean and revealing all this to the United States," said Abuza. "We might get some very vague commitment in terms of their commitment to denuclearization but actual reversal of their program and dismantling of it is very unlikely," he said.

Iran nuclear deal

Complicating the picture is the fact that Washington pulled out of the nuclear deal with Iran which the previous U.S. administration under Barack Obama brokered. "If you're in the North Korea position, and you see Americans walking away from a commitment that they signed very quickly and (are) willing to do so unilaterally without the support of their key European allies, that should send very clear signals to the North Korean advisors to Kim Jong Un, that anything they sign with the United States might not be held long," said Abuza. With the North Koreans watching U.S. political developments, it's important that Trump gets bipartisan support for any agreement he reaches with Kim, said Abuza, adding that the deal will also need the support of North Korea's allies China and Russia, as well as neighboring Japan and South Korea.

Ending the Korean War