The United States, China, Britain, Germany and other governments at the meeting in Chengdu in western China pledged to use spending, monetary policy and regulatory reforms to strengthen growth.
"We will carefully calibrate and clearly communicate our macroeconomic and structural policy actions to reduce uncertainty, minimize negative spillovers and promote transparency", the communique said.
The spectre of protectionism, highlighted not only by Brexit but also by U.S. Republican presidential candidate Donald Trump's "America First" rhetoric and talk of pulling out of trade agreements, was also a focus for the policymakers.
"It's right at the top of the agenda here at the G20", Mr Hammond said at the end of the two-day meeting of the Group of 20 leading economies in the Chinese city of Chengdu. Philip Hammond faced concerns about how quickly the United Kingdom prepared to continue with formal negotiations to leave the EU.
The G20 officials' meeting in the southwestern Chinese city of Chengdu will be a debut of sorts for Britain's newly-appointed finance minister Philip Hammond, who will be grilled about the UK's plans for keeping up economic growth.
Lew underscored the need to use all policy tools, including fiscal and monetary policies as well as structural reforms, to shore up global economic growth, the US officials said. "Due to current developments, we restate our determination to utilize all policy tools- financial, financial and structural- separately and jointly to attain our objective of strong, sustainable and well balanced development", it stated.
Li said the International Monetary Fund hike put "pressure" on China to "maintain growth and stability", but he vowed to push economic reforms such as making its yuan currency trade more freely - something Beijing has repeatedly promised, and a key sticking point with the United States and other major trade partners. "We can not shoulder the major responsibilities of the world economy", Li said after the "1+6" talks with global agency chiefs, including the worldwide Monetary Fund chief Christine Lagarde and World Bank president Jim Yong Kim.
Sunday's statement says the referendum increased global economic uncertainty. G20 members are ready to actively respond to the potential economic and financial impact brought by the British referendum.
Tycoon Donald Trump sealing the Republican party nomination in the U.S. presidential race, where he will face Democrat Hillary Clinton, could add uncertainty if the contest is close.
"China has just implemented the reform by collecting tax from cross-border e-commerce industry, the level of which has been for long way lower than that of value-added tax", Lou said., "Low taxation level on imported goods does not help drive innovation for domestic companies".
On China's bloated steel and coal sectors, Li said China was cutting about 5 million tonnes of steel production capacity and 100 million tonnes of coal output.