WASHINGTON - Singapore's Minister for Foreign Affairs Vivian Balakrishnan says he is "a little bit hopeful" about relations between China and the United States after the two countries' foreign ministers met in New York on Friday.

"Clearly if you look at the rhetoric and the actions that have occurred across the Taiwan Strait in recent weeks it is an area of concern - I would even say grave concern," Dr Balakrishnan told The Straits Times after delivering his speech at the United Nations General Assembly on Saturday.

"But I am a little bit hopeful because...there has been a meeting face to face… (and) I think both sides understand the gravity of the situation."

He said he hoped that "cool heads and good sense" will prevail and that the US and China would avoid the possibility of mishaps or miscalculations occurring.

"But that is an expression of hope. We will have to wait and see," he said.

He also noted that the next two to three months would be a vital period to de-escalate the situation, and for tensions between the two countries to be dampened.

This included upcoming summits, which presented opportunities for the two global powers to meet.

He said: "I hope that the presidents of China and the United States will meet face to face, arrive at some kind of modus vivendi, and set the tone so that officials, ministers, all the stakeholders involved, can conduct constructive, hopefully positive negotiations."

Given multiple global anxieties - from the war in Ukraine to food and energy prices to US-China relations and climate change - the mood at the 77th UN General Assembly and related meetings in New York was "sombre" Dr Balakrishnan told Singapore media.

He noted that Europe and Russia were still very far apart on the issue of Ukraine.

"There is a very wide gap," he said. "My sense of it right now as far as Ukraine is concerned is that conditions are not right for negotiations."

He said that Russia's mobilisation of reservists to strengthen its army in Ukraine was a bad sign.

"(It) shows escalating tension and the fact that you are not going to get a quick resolution," he added.

Dr Balakrishnan said he had met with foreign ministers and leaders of more than 60 countries in five days in New York.

Multilateral meetings included that of the Forum of Small States (FOSS), which celebrated its 30th anniversary on the sidelines of the UN General Assembly.

FOSS has grown from 16 countries when it first started to 108 member countries, forming a majority in the UN.

The small states' priorities centre on multilateralism, a rules-based system with the UN charter at its heart, said Dr Balakrishnan.

This means encouraging bigger powers to act with self-restraint and to comply with international law, he said.

Singapore also convened the Global Governance Group, which acts as a bridge between the Group of 20 (G-20) countries and the non G-20 countries in the larger UN membership.

Asked about the situation in Myanmar, which is currently governed by the military, Dr Balakrishnan said he was pessimistic.

"Our view remains that the only way out of this quagmire is for political reconciliation, and for good faith discussions and negotiations between all the parties" he said.

Talks must involve National League for Democracy leader Daw Aung San Suu Kyi and the military led by Senior General Min Aung Hlaing, he said.

"There has to be a proper meeting (and) a proper attempt to put the interests of their country first, to set aside the differences and to try to negotiate," he said. "Without that happening, you will not get a solution."

He stressed, however, that this was an internal matter for Myanmar to resolve, and that external intervention was not the answer.

"Asean was never set up to interfere in internal matters, and nor should we," he said, referring to the South-east Asian regional bloc.