News that China will allow local governments to use proceeds from special bonds as capital for investment projects came after the United States and Mexico on Friday reached a deal to avert US tariffs on Mexican goods, lifting copper and other metals.
Benchmark copper on the London Metal Exchange (LME) traded up 0.7pc at $5,916 a tonne in official rings after reaching a high of $5,947.50.
Global stock markets also rose and Chinese equities surged about 2pc.
Fears that trade disputes will damage economic growth and metals demand had helped push copper prices down 15pc from an April high to a five-month low of $5,740 last week.
"Optimism is stemming from talk of additional stimulus out of China," Capital Economics analyst Ross Strachan said.
"It's not a major surprise that markets have latched on to some positive news. It's been a bit of a bloodbath recently," he said, adding that copper was likely to end the year around current levels.
MEXICO: Mexico and the United States may explore additional steps next month to restrict illegal immigration from Central America, with the threat of tariffs hanging over Mexico.
CHINA: China will respond firmly if the United States insists on escalating trade tensions, the foreign ministry said. US Commerce Secretary Wilbur Ross said this month's G20 summit will help push U.S-China trade talks forward but no final agreement was expected there.
YUAN: China's central bank said it will sell yuan-denominated bills in Hong Kong in late June, which some analysts said was aimed at stemming a sharp weakening in the yuan.
DOLLAR: The dollar has weakened from last month's two-year highs, supporting metals by making them cheaper for buyers with other currencies.
CHINA PREMIUMS: Chinese Yangshan copper import premiums at $59 have risen from two-year lows of $47 last month.
"As the premium has started to recover, we expect China's import appetite to recover again in June," said Argonaut Securities analyst Helen Lau.
LEAD: LME lead traded up 0.9pc at $1,905 a tonne, as the premium for cash metal over the three-month contract surged to $43.50, the highest since early 2017, pointing to a shortage of nearby supply.
Stocks of lead in LME-registered warehouses are near the lowest since 2009.
OTHER METALS: LME aluminium did not trade but was bid up 0.5pc at $1,783 a tonne after touching a 29-month low on Monday. Zinc traded 1.8pc higher at $2,520, nickel also traded up 1.8pc at $11,885 and tin was bid down 0.2pc at $19,200.