The Philippines and the United States reached agreement on Friday on a new security accord allowing American military forces to share local bases for maritime and humanitarian operations, a senior Philippine defence officials said.

The two oldest allies in the Asia-Pacific region had been negotiating a new military deal for nearly eight months to increase US rotational presence in the Philippines and improve its former colony's defence capability.

Pio Lorenzo Batino, Undersecretary of Defence and chair of the Philippine negotiating panel, said both sides had reached a "consensus on key points" during an eighth round of talks.

"The draft provisions on key points of an enhanced defence cooperation will be submitted to the president for his review," Batino said in a statement. The accord is expected to be signed during President Barack Obama's April 28-29 visit to Manila.

The agreement will be a highlight of Obama's visit to Asia, underscoring the US ‘rebalance’ to Asia despite preoccupations elsewhere, including Ukraine, Iran and Syria.

"No, I don't think there should be any doubts to the US rebalance to Asia," said Jose Cuisia, the Philippine ambassador to the United States.

Cuisia said the Philippines stood to receive more US military assistance once the pact was signed. For this year, the US allocated about US$50 million in foreign military financing, nearly double the previous year's sum.

"It's up to the Philippine Armed Forces to determine what they need," Cuisia said. "I think they are looking at getting newer vessels."

He said Washington also promised to help acquire long-range maritime patrol aircraft to enable the Philippines to keep closer watch on its maritime borders in the East Sea.

Military sources said the agreement would increase ship visits and deployment of surveillance aircraft. Last year, there were 149 US navy ship visits, up from 68 in the previous year.

Batino said the agreement complied with the Philippine constitution, meaning US forces will have no permanent presence and will set up no military bases.

"United States access to and use of the armed forces of the Philippines facilities and areas will be at the invitation of the Philippines," he said.

The agreement, he said, excluded the import of nuclear weapons and also had "robust provisions on the protection of environment, human health and safety".

The United States had two large military bases in the Philippines up to November 1992. The Philippine Senate voted to evict the American military forces in 1991, ending 45 years of special relations from Manila's independence in 1946.

The US military returned in 2000 after Manila signed an agreement allowing the two sides to train and hold exercises together on conventional and counter-terrorism operations.