Under Ferdinand Marcos Jr., the Philippines has shifted its focus back to the United States and their support for the Southeast Asian nation's maritime disputes with China.

This timeline shows the key events that have heightened tensions between China and the Philippines this year:

JAN 3: The Philippines and United States conduct their second joint patrol of the South China Sea, while China is conducting similar activities with its air and naval forces in this disputed waterway.

The Philippines has condemned China's coast guard for their "illegal and reckless" actions, which led to the collision of a Chinese ship with a Philippine vessel during a resupply for troops on Second Thomas Shoal. China claims that the Philippine vessels intruded illegally into the waters near the Second Thomas Shoal.

China's coastguard has announced that it has taken action against Philippine vessels resupplying troops on the Second Thomas Shoal. The Philippines condemned the actions, including the use water cannon.

APRIL 7, 2019 - The US, Japan and Australia have conducted "maritime cooperation activity" within the Exclusive Economic Zone of the Philippines in the South China Sea.

APRIL 11: The United States Army deploys the ground-based Typhon system in joint military drills, marking the first time that the mid-range capability of the United States Army has been deployed to the Indo-Pacific.

APRIL 16: The Philippines sends its coastguard patrol ship Teresa Magbanua, to Sabina Shoal, to monitor what they suspect to be small-scale reclamation activity by China. China denies this accusation.

APRIL 30, 2019 - The Philippines accuses China of harassing and damaging two of their boats at Scarborough Shoal. They reject Beijing's claim that they had expelled these vessels from the disputed shoal.

May 15: A civilian flotilla consists of Philippine vessels that sail towards Scarborough Shoal in order to assert Manila’s maritime rights, and to distribute supplies to the fishermen who are anchored there.

JUNE 15: Philippines submits a claim to the United Nations for extending the continental shelf of the South China Sea.

JUNE 17: A Philippine sailor lost a finger as a result of what the Philippine military described as an "intentional high speed ramming by the Chinese Coast Guard" to disrupt a supply mission for troops on Second Thomas Shoal. China disputes Manila’s account and says the necessary measures were taken in a professional manner.

JULY 2, 2016 - During high-level discussions on the management of disputes in South China Sea, Philippines and China agreed to "restore confidence" and "rebuild trust" to better handle maritime disputes.

JULY 8, 2008 - Philippines & Japan sign a landmark military agreement allowing the deployment of forces in each other's territory.

JULY 17, 2017 - Philippines & China agree to establish new lines of communications to improve their handling maritime disputes.

JULY 22, Philippines and China come to an "agreement provisional" regarding resupply missions for a Filipino naval vessel stranded in Second Thomas Shoal.

JULY 27, - The Philippines successfully completed a resupply mission to its troops on Second Thomas Shoal.

AUG 2: Philippines and Japan conduct first joint military exercise in the South China Sea.

AUG 9: The Philippines and Vietnam conduct their first joint coast guard exercise.

AUG 10: Philippines accuses China of performing "dangerous maneuvers" when it dropped flares into the path of an aircraft of the Philippine Air Force conducting a routine air patrol over Scarborough Shoal.

AU6 19: China and the Philippines accuse each of performing dangerous maneuvers and ramming vessels near Sabina Shoal.

AUG 24: Philippines accuses China for "unjustifiably", deploying flares on Subi Reef, occupied by China, while a Manila aircraft conducted patrols.

AUG 25: Philippines and China clash over a Manila-led resupply for fishermen.

AUG 31: Philippines and China accuse each other of deliberately ramming Coast Guard vessels near Sabina Shoal. This is their fifth maritime encounter in a single month.

SEPT 15: The Philippine Coast Guard vessel Teresa Magbanua returns to port in Port Angeles after a 5-month deployment at the contested feature.

SEPT 23: The Philippines claims that a Chinese helicopter approached and shadowed its fisheries office aircraft near Scarborough Shoal while it was on patrol.

SEPT 28: The Philippines, Australia, Japan, New Zealand, and the U.S. participate in a joint maritime exercise with a portion the South China Sea, while China conducts its own military exercises in the disputed watersway.

OCT 8: The Philippines accuses China of firing water cannons at its ships that were bringing supplies to Scarborough Shoal fishermen.

OCT 11: The Philippines say a Chinese maritime militia boat side-swiped a government fishing vessel near Thitu Island while on patrol.

NOV 8: The Philippines signs two maritime zone laws and an archipelagic maritime lanes law, which define maritime entitlements as well as designated sea and aerial routes. This angers Beijing.

DEC 4: China and the Philippines face off in Scarborough Shoal accusing each of aggressive behavior.

DEC 6: Japan, the Philippines, and the U.S. participate in a maritime cooperation activity within Manila's exclusive Economic Zone.

(source: Reuters)