During Philippines President Ferdinand Marcos' four-day trip to the US to meet with President Joe Biden, reporters were told by an anonymous senior US official that both nations are "in a deeply consequential period in terms of our Indo-Pacific engagements."

This comes a few days after South Korean President Yoon Suk Yeol visited the US and after a January meeting between Biden and Japanese Prime Minister Fumio Kishida.

"It's really the first kind of meeting at this level and intensity between the United States and the Philippines in decades," the official added. 

As China has been discussing the sovereignty of the South China Sea more openly and confidently, the US and its Asian allies have remained on high alert amid pre-existing tensions over Taiwan, which has prompted joint military exercises. 

The US and Philippines wrapped up their largest-ever military training after troops conducted a joint fire drill in the contested waters of the South China Sea last month. Groups of the two armies blasted a supposed enemy warship placed in disputed waters North of Manila.

Before leaving for the US, Marcos indicated and emphasized that he "will not allow the Philippines to be used as a staging post for any kind of military action." However, just less than a month ago, the Philippines announced the location of four additional military bases to be used by US troops, with one site near Taiwan.

The locations of four additional military bases, and another not far from Taiwan -- agreed upon under the Enhanced Defense Cooperation Agreement (EDCA) of 2014 -- were revealed by Manila last month.

Read more: US warns Beijing of military response if China targets Philippine army 

The agreement permits the rotation of US soldiers through the bases, as well as the storage of defense supplies and equipment there. It has drawn criticism from Beijing, which recently claimed that it was a result of "US efforts to encircle and contain China through its military alliance with this country," its embassy in the Philippines said.

US bases aim for being 'better allies'

The senior official claimed that the Philippines is "looking for reassurance and a strong desire to maintain peace and stability in this complex period," adding that "recent events have caused much greater focus in both capitals on taking the necessary steps to up our game, to improve engagement on the security side between the United States and the Philippines."

According to the official, "bilateral defense guidelines" would witness "a series of steps to support the Armed Forces of the Philippines modernization."

In response to the presence of US bases in the Philippines, White House National Security Council Spokesperson John Kirby stated that the bases remain part of the Filipino military and "every single step of the way will be done in complete coordination... it's about our ability to be better allies to one another and meet our commitments to each other."

The US official concluded by confirming that Biden is due to meet soon in a trilateral format with the leaders of Japan and South Korea before leaving for Australia to convene with the Quad group: Australia, India, Japan, and the United States.