Challenges surround the US Secretary of State during his trip to Asia.

When Rex Tillerson was sworn in as U.S. Secretary of State, President Donald Trump declared he would set a "clear focus on foreign policy issues."

Secretary of State Tillerson will need to demonstrate this during his first trip to Asia, beginning March 15, amidst heightened regional tensions. North Korea's missile program is progressing more rapidly and sophisticatedly, threatening the U.S. and its two key allies, Japan and South Korea. Meanwhile, South Korea is reeling from a political scandal that led to the impeachment of President Park Geun-hye.

US Secretary of State Rex Tillerson. (Photo: Reuters)

Tillerson will need to convince both countries that continued commitment to the United States is in their best interests. However, the new Secretary of State's diplomatic skills will be tested in the final leg of his journey, as he will be the first member of President Trump's Cabinet to visit China.

CNN outlines the challenges Secretary of State Tillerson faces in each country he visits:

Japan

The most pressing issue facing the new US Secretary of State in Japan, as well as across the region, is the growing nuclear threat from North Korea.

North Korean leader Kim Jong Un test-fired a ballistic missile while Japanese Prime Minister Shinzo Abe was visiting U.S. President Donald Trump in Florida. The timing of the launch led many analysts to believe it was a message Pyongyang wanted to send to Tokyo.

Last week, when North Korea launched four ballistic missiles simultaneously, its media implied it was a practice attack on U.S. military bases in Japan, where approximately 52,000 U.S. troops are stationed.

Secretary of State Tillerson will meet with Prime Minister Abe and his counterpart Fumio Kishida. The host country wants the US to reaffirm Tokyo's commitment to being Washington's closest and most trusted ally in the Asia-Pacific region.

Tensions between Japan and South Korea, another major U.S. ally, could pose a challenge for Tillerson as he seeks to contain North Korea.

Last January, the Japanese ambassador to Seoul was recalled due to a controversy surrounding the issue of Japanese military comfort women before and during World War II. The US Secretary of State will have to find a way to encourage the two allies to resolve their differences so that all three countries can focus on the North Korea issue.

Korea

The main challenge for South Korean officials when Tillerson arrived was convincing the head of the U.S. State Department that things in Seoul were continuing as normal after Park's impeachment.

Tillerson will meet with Acting President Hwang Kyo-ahn and Secretary of State Yun Byung-se.

When U.S. Defense Secretary James Mattis visited last month, he said what South Koreans wanted to hear – that Washington was committed to a "overwhelming" response to any attack from North Korea. Now, South Korean officials want Tillerson to deliver similar messages.

In addition, Tillerson's visit to South Korea comes amidst complaints from Seoul that it is facing economic sanctions from Beijing for agreeing to the installation of THAAD – a missile defense system that Washington argues is necessary to counter the missile threat from North Korea.

With Park having left politics, Tillerson wants the new South Korean leader to honor the aforementioned agreement. South Korea will hold early elections to choose a new president at the end of May.

The first components of THAAD were delivered to South Korea last week, and the full defense system will be fully operational as early as July.

China

Tillerson's first priority in the planned meetings in Beijing is to detail the summit in Florida between President Donald Trump and President Xi Jinping in April. This will be the first meeting between the two leaders, at a time when US-China relations are widely considered the most important in the world.

Another important issue to address will be the ongoing crisis on the Korean Peninsula. Since the beginning of 2016, Pyongyang has conducted two nuclear tests and launched dozens of ballistic missiles, raising tensions in the region. And the Trump administration wants China to do more to restrain its neighbor.

It is highly likely that China will bring up the THAAD system and the Gray Eagle fighter jets in South Korea. In recent days, Beijing has expressed considerable displeasure on both issues.

Secretary of State Tillerson may also raise the issue of China's increased presence in the South China Sea. During his confirmation hearing in the Senate, he stated that China should not be allowed access to the artificial islands it has illegally constructed.

The US Secretary of State's visit to China could set the tone for the upcoming meeting between Trump and Xi.

According to Vietnamnet