US wants missile bases in Asia soon, after pulling out of treaty with Russia

US Defense Secretary Mark Esper said on Saturday that he was in favour of placing ground-launched, intermediate-range missiles in Asia relatively soon, a day after the United States withdrew from a landmark arms control treaty.

Esper's comments are likely to raise concern about an arms race and could add to an already tense relationship with China.

"Yeah, I would like to," Esper said, when asked whether he was considering placing such missiles in Asia.

"I would prefer months ... but these things tend to take longer than you expect," he told reporters travelling with him to Sydney when asked about a timeline for when the missiles could be deployed.

The United States formally left the Intermediate Nuclear Forces (INF) treaty with Russia on Friday after determining Moscow was violating the treaty, an accusation that the Kremlin has denied.

On Friday, senior US officials said that any deployment of such weaponry would be years away.

Within the next few weeks, the United States is expected to test a ground-launched cruise missile, and in November, the Pentagon will aim to test an intermediate-range ballistic missile. Both would be tests of conventional weapons - and not nuclear.

The 1987 pact banned ground-launched nuclear and conventional ground-launched ballistic and cruise missiles with ranges of 500-5500km.

US officials have been warning for years that the United States was being put at a disadvantage by China's development of increasingly sophisticated land-based missile forces, which the Pentagon could not match due to the US treaty with Russia.

The United States has so far relied on other capabilities as a counterbalance to China, like missiles fired from US ships or aircraft. But advocates for a US land-based missile response say that is the best way to deter Chinese use of its muscular land-based missile forces.

"I don't see an arms race happening, I do see us taking proactive measures to develop a capability that we need for both the European theater and certainly this theater," Esper said, referring to the Asia-Pacific region.

While no decisions have been made, the United States could theoretically put easier-to-hide, road-mobile conventional missiles in places like Guam.

Esper did not say where in Asia he was considering placing missiles, but he is expected to meet senior regional leaders during his visit to Asia.